Pulse Reverse Electrodeposition of Ni - Nano SiC Coatings on AISI 1018 Mild Steel: A Study of Hardness, Wear and Corrosion Resistance

Abstract

This research investigates the enhancement of Ni-SiC composite coatings on AISI 1018 steel through pulse reverse electrodeposition, systematically varying the concentration of nano-Silicon Carbide (nano-SiC) at 1%, 2%, 3%, 4%, and 5%. The study aimed to assess the effects of nano-SiC content on the microhardness, corrosion resistance, and wear performance of the composite coatings (NHC1-NHC5). The results showed a clear trend of increasing microhardness with higher nano-SiC concentrations, starting with a baseline hardness of 131 HV for AISI 1018 steel. The highest hardness was achieved with the NHC5 specimen (5% SiC), reflecting a 5.76% increase compared to the NHC4 specimen. X-ray diffraction analysis confirmed the incorporation of nano-SiC into the nickel matrix, with characteristic SiC peaks observed, indicating its presence in the coating. Increasing nano-SiC content significantly improved the corrosion resistance, as the best result was observed in the NHC5 coating that exhibited the lowest corrosion rate and the material loss. Furthermore, the wear performance was significantly improved, with the NHC5 coating showing a 93.12% reduction in specific wear rate and a 62.93% reduction in coefficient of friction compared to the reference material/condition. These findings were also corroborated through microscopic analysis that revealed minimal wear and corrosion damage on the NHC5 specimen. It was shown that higher nano-SiC content significantly enhances the hardness, corrosion, and wear resistance of Ni-SiC composite coatings on AISI 1018 steel.

Keywords:
Ni-SiC composite coating; AISI 1018 mild steel; Pulse Reverse Electrodeposition; Corrosion; Salt-spray test; Nano-reinforcements; Tribological performance; Specific Wear Rate

1. Introduction

AISI 1018 mild steel is a commonly used low-carbon steel predominantly composed of iron. It is known for its good machinability, toughness, and strength. Its nominal chemical composition includes approximately 0.18% carbon and 0.60% manganese, along with negligible amounts of phosphorus and sulfur. Welding, forming, and machining can be performed with this composition, giving steel the versatility for usage in shafts, gears, pins, and structural elements for the machine, automotive, and construction industries¹. Although AISI 1018 mild steel has the advantage of ease of fabrication, it has disadvantages of poor wear resistance, poor corrosion resistance, and poor surface hardness. However, these limitations prohibit its application in high-demand environments, particularly where its elements are exposed to adverse conditions, abrasive wear, and corrosive mediums². Facing such obstacles, composite coatings are developed to contribute to enhancing the surface properties of AISI 1018 steel, including wear resistance, corrosion resistance, surface hardness, etc. It can deposit coatings with hard ceramic particles (such as nano-Al₂O₃ or SiC) and then deposit coatings with the steel being able to withstand much harder applications, reduce costs in maintenance, and increase in service life³. Ni- Al₂O₃ composite coatings are found to be one of the promising coating options. These are coatings of Ni and Al₂O₃ that offer advantages for surface finishing applications. Nickel is known for its resistance to corrosion, high electrical and thermal conductivity, and accuracy of thermal expansion, while the high microhardness, wear resistance, and chemical stability at high temperatures offered by alumina add up to the superior coating durability. Particularly for their good abrasion resistance, heat resistance, and corrosion protective properties, Ni-Al₂O₃ coatings are an alternative to traditional coatings, such as chromium⁴. Ni coatings produced by pulse electrodeposition, especially when oxide or carbide particles are added, are high-performance coatings. Parameters like pulse frequency and duty cycle allow for the fine-tuning of coating properties. Coatings produced in this manner are harder, smoother, denser, and more uniform with excellent corrosion and wear resistance. The coating durability is improved because of an improved microstructure and fewer pinholes; hence, this coating finds ready applications in demanding applications in machine tools, automotive, and aerospace industries⁵.

The development and performance of Ni-Al₂O₃ composite coatings have been under study in several researches. Looking at the specific case, six-layer multilayer coatings consisting of Ni– Al₂O₃ nanocomposite were electrodeposited on mild steel using pulse electrodeposition and ultrasound agitation. Alternatively, these coatings showed increased wear resistance at higher duty cycles and frequencies, and corrosion testing demonstrated that there is an active–passive transition and that structure does play a part in corrosion resistance⁶. Monodispersed alumina particles were synthesized and included in the Ni-Al₂O₃ composite coating that increased the coating’s wear resistance and friction performance over the pure Ni coating. Coatings made of Ni-Al₂O₃ were shown to be more resistant to corrosion than coatings made of pure Ni⁷. In order to enhance other properties of AISI 1018 steel, other composite coatings have been developed. Stainless steel 304 was coated with Ni-TiO₂ composite coatings through pulsed electrodeposition. The parameters, which included current density, duty cycle, and frequency, were optimised which led to an improvement in the surface roughness, microhardness, corrosion resistance, and wear resistance of the material. Further post-heat treatment at 400ºC improved the properties still further and, on this basis, found greater corrosion protection efficiency than the as-coated samples⁸.

Similarly, electroless Ni–P–Al₂O₃ nanocomposite coatings were deposited on steel, and the addition of alumina nanoparticles increased microhardness and wear resistance, though their presence slightly impacted corrosion resistance⁹. By using pulsed electrodeposition with changing amounts of alumina, composite coatings consisting of nickel-gamma alumina (Ni–γAl₂O₃) were successfully synthesized. Coatings with 10 g/L alumina exhibited uniform dispersion and significant improvements in mechanical properties, including increased hardness, young’s modulus, and yield strength compared to pure Ni coatings¹⁰. Additionally, multilayer coatings such as Ni/nano-Al₂O₃ composite coatings showed similar hardness and tribological properties to monolayer coatings but prevented microcrack initiation, improving coating thickness and wear resistance¹¹. Ni-P-NiTi and Ni-P-Ti are two examples of other composite coatings that have been created in order to improve the resistance of AISI 1018 steel to wear and corrosion. The Ni-P-NiTi coatings demonstrated significantly improved corrosion resistance compared to as-deposited Ni-P coatings, especially under dynamic and abrasive conditions. Similarly, Ni-P-Ti coatings exhibited enhanced erosion–corrosion resistance, with Ti particles acting as barriers to improve coating durability¹²,¹³. Some studies have also been devoted to employing various nanocomposite coatings to enhance the tribological properties of AISI 1018 steel. For instance, Ni–Al₂O₃ composite coatings on mild steel have enhanced wear resistance, and the wear rate is dependent on normal load and sliding distance. Wear mechanisms in other Ni-based composite exfoliated graphite particles concluded that the presence of nano-Al₂O₃ particles in the Ni matrix reduced wear, especially under abrasive conditions¹⁴. Ni-P-NiTi composite coatings displayed superior erosion–corrosion-resisting properties compared to the AISI 1018 steel substrate and could be used in very aggressive environments¹⁵.

Other Ni–P composite coatings, enriched in graphene, were manufactured to improve their erosion and corrosion resistance for the hydrocarbon industries. Ni-P coatings with graphene showed improved corrosion and wear resistance and good durability under harsh conditions¹⁶. In addition, electroless composite coatings with graphene oxide (rGO) were investigated in terms of their effect on wear resistance. However, improved tribological behavior was observed with lower rGO concentrations, suggesting that rGO presents the possibility of improving the performance of coatings in demanding conditions¹⁷. In the last, Co–Ni–Fe nanoparticles were electro-deposited onto mild steel to improve coating thickness and hardness, and deposition time influences the corrosion and wear resistance of nanoparticles. The coatings showed uniform morphology and exhibited enhanced performance, which made the coatings suitable for applications needing high surface durability¹⁸.

The features of Ni–SiC coatings are determined by a number of factors, the most important of which are the electrodeposition parameters, which include the pulse frequency, duty cycle, and current density. A reduction in duty cycle coupled with an increased pulse frequency typically promotes grain refinement, thereby enhancing the coating’s hardness and uniformity¹⁹. The constitution of the electrolyte bath is also of considerable importance; the introduction of SiC nanoparticles into a nickel bath facilitates co-deposition, while surfactants such as Tween 60 and Span 80 serve to improve particle dispersion, yielding more homogeneous coatings²⁰. The selection of the substrate material constitutes another pivotal consideration. Ni–SiC coatings have been successfully implemented on various substrates, encompassing steel, brass, carbon steel, and stainless steel. The inherent properties of the substrate can impinge upon adhesion, corrosion resistance, and the overall performance of the coating. In addition, the coating's wear resistance is directly affected by the concentration of SiC nanoparticles in the bath; typically, larger concentrations provide better reinforcement²¹-²⁶. Regarding inherent properties, Ni–SiC coatings commonly exhibit substantially elevated microhardness relative to pure nickel coatings, particularly when pulse deposition parameters are optimized. Their wear resistance is also markedly improved as a result of the incorporation of hard SiC particles, with further advantages observed under water-lubricated conditions. Furthermore, corrosion resistance is augmented in comparison to uncoated substrates, rendering these coatings well-suited for deployment in harsh operational environments. The surface morphology of the coatings may exhibit variability contingent upon deposition parameters, ranging from nodular to acicular structures²³,²⁷. Contemporary advancements, such as ultrasound-assisted pulse electrodeposition, have further refined the quality of these coatings. This technique influences surface morphology, phase composition, and wear performance, thereby presenting a propitious avenue for high-performance coating applications²⁸,²⁹. To conclude, comprehensive testing—encompassing microhardness, wear, and corrosion assessments—conducted under diverse environmental conditions is indispensable for affirming the industrial applicability of Ni–SiC composite coatings. An important potential for composite coating, especially including nanomaterials, is demonstrated in these studies as a way of improving AISI 1018 mild steel. These coatings improve corrosion resistance, wear resistance, and surface hardness and, in this way, increase the service life and reliability of components operated under harsh operating conditions in several industrial applications.

The existing gap in the literature regarding composite coatings is addressed by the current research on Pulse Reverse Electrodeposition (PRED) of Ni – Nano SiC coatings on AISI 1018 mild steel. Ni-based coatings with materials such as Al₂O₃, TiO₂, and graphene have been widely researched in order to improve wear resistance, corrosion resistance, and surface hardness, but incorporating nano-Silicon Carbide (SiC) in Ni coatings is yet to be explored. Concentration of the nano-SiC powder (1%, 2%, 3%, 4%, and 5%) was studied in this research work to improve the properties of composite Ni- SiC coatings on the AISI 1018 steel. The study, innovatively, employs the PRED technique, which has almost not been studied in Ni-nano SiC coatings, where coatings are achieved with improved uniformity and mechanical properties by alternatively running the electrodeposition process as cathodic and anodic pulses. This study stands out by providing a comprehensive evaluation of the coatings' performance under real-world harsh environments. It assesses both wear resistance using tribological tests (pin-on-disc) and corrosion resistance under salt spray corrosion behaviour, offering a dual approach to understanding the coatings' durability. Ultimately, the research aims to optimize Ni-SiC composite coatings for industrial use, enhancing AISI 1018 mild steel's performance in automotive, machinery, and structural applications. By addressing the underexplored use of nano-SiC in Ni coatings, this study contributes significantly to advancing surface engineering techniques for improved wear and corrosion resistance in challenging environments.

2. Materials and Methods

2.1. Starting materials

AISI 1018 (UNS G10180) mild carbon steel was chosen as the substrate material for the deposition of Ni-SiC composite coatings in this study. The steel's composition, detailed in Table 1, includes approximately 0.18% carbon, which is characteristic of low-carbon steels, and the material has a density of 7.87 g/cm³. The elemental makeup of AISI 1018 was sourced from Bharath Metals, Chennai. The Ni and nano-SiC particles used in the electrodeposition process were supplied by Nanoshell, India, with the SiC particles having an average size of 45 nm, ensuring a high surface area and improved interaction with the Ni matrix. AISI 1018 mild steel has notable mechanical properties, with an ultimate tensile strength of 440 MPa, allowing it to endure substantial loads before fracturing under tension. Its yield strength of 370 MPa marks the stress level where permanent deformation begins. Additionally, the steel demonstrates reasonable ductility, indicated by a 15% elongation, which permits it to be shaped to some extent before failure (ASTM A370)³⁰. With a Vickers hardness of 131 HV, AISI 1018 is considered relatively soft, a characteristic typical of low-carbon steels (ASTM E92)³⁰. These properties make it a cost-effective, versatile material suitable for structural and manufacturing applications where high strength is not a critical factor³¹.

Table 1
Elemental composition of AISI 1018 steel.

Element	C	Mn	S	Si	P	Ni	Al	Cr	Cu	Fe
Wt%	0.18	0.83	0.022	0.19	0.012	0.13	0.03	0.13	0.175	Bal.

2.2. Electrodeposition process

The pulse electrodeposition process involved the mild steel substrate acting as the cathode, while a Ni plate measuring 100 mm × 30 mm × 10 mm served as the anode, facilitating the deposition of the Ni-SiC composite coating onto the steel surface. Before beginning the electrodeposition process, the base materials underwent thorough cleaning to remove any contaminants. The AISI 1018 plates were polished with 2000-grade SiC sheets to achieve a smooth surface finish. After polishing, the plates were carefully immersed in acetone for ultrasonic cleaning, followed by a room temperature washing with distilled water. This multi-step cleaning procedure ensured the removal of surface impurities, providing a clean substrate for high-quality deposition.

A bath with the composition given in Table 2 was prepared with a nickel Watts-type bath for Ni-SiC electrochemical deposition. Without an inhibitor such as sodium dodecyl sulfate, SiC nanoparticles will quickly aggregate too much and will not successfully disperse in the bath. To minimize agglomeration of SiC nanoparticles, the electrolyte bath was subjected to continuous magnetic stirring for 16 hours prior to electrodeposition to promote uniform dispersion. Additionally, sodium dodecyl sulfate was introduced as a surfactant to improve particle stability and reduce clustering. Nonetheless, some degree of agglomeration may persist, particularly at higher SiC concentrations (≥4%), potentially affecting coating homogeneity and mechanical performance. This limitation is acknowledged and should be considered when evaluating the results, especially for coatings with elevated nano-SiC content. The SiC nanoparticles, which were meticulously introduced to the electrolytic solution, had a purity level higher than 99% and an average particle size of 45 nm. To ensure complete integration throughout the deposition process, an electrolyte with an appropriate SiC content of 1–5 g/L was maintained. The electrolyte pH was brought down to a strict 4 range by adjusting the concentration of the completed solution. Table 3 further shows that the plating solution used is kept at a constant temperature of 50°C. The deposition process was conducted in a plating cell equipped with a thermal mixer, which managed the temperature and humidity levels and maintained consistent conditions. The total volume of the plating cell was 250 mL, which was found to be appropriate enough for mixing and effective distribution of SiC particles in the electrolyte bath.

Table 2
Electrodeposition bath formulation.

Nickel Sulfate (NiSO4·6H2O)	300 g/L
Boric Acid (H3BO3)	30 g/L
Nickel Chloride (NiCl2·6H2O)	30 g/L
pH	4.0±0.2
Nano-Silicon Carbide (SiC) Particles	1-5 g/L

Table 3
Pulse reverse electrodeposition parameters.

Pulse Duty Cycle	50%
Pulse Frequency	100 Hz
Current Density	600 A/m2
Plating Temperature	50ºC±2ºC
Deposition Time	15 minutes

AISI 1018 steel substrates were coated with Ni-SiC composite coatings by using the pulse reverse current technique (Figure 1). The method comprises alternation between anodic and cathodic pulses for controlling nickel deposition and incorporates SiC particles. Important parameters, including current density, pulse frequency, and plating period, are chosen via experiments to optimise deposition efficiency. Uniform and dense coatings are assured by controlled microstructure and thickness; thus, the pulse reverse current technique ensures consistent coating quality with improved mechanical properties, which was continuously monitored throughout the deposition process. It was found that the Ni-SiC composite layer's coating thickness was about 30 µm, using a calibrated micrometer. This thickness was found to be consistent across all coated specimens and is considered optimal for achieving improved corrosion and wear resistance without sacrificing coating properties.

Figure 1
a) AISI 1018 steel specimen and b) NHC5 specimen (Ni-5% Nano SiC coating on AISI 1018 steel).

Upon completion of the deposition procedure, the samples coated with Ni-SiC composite were removed from the plating cell, and any surplus electrolyte was removed using distilled water. Once the samples were brought to room temperature, they were dried to improve the coating's adherence and characteristics. A total of six distinct coatings were created in this work by applying PRED to AISI 1018 mild steel substrates and then adjusting the quantity of nano-SiC particles in the nickel-based electrodeposition solution. The nano-SiC powder was mixed mechanically into the Ni coating material. For the NC, a standard nickel coating was put on the steel base. Then, five other experiments, NHC1 to NHC5, were done with nano-SiC contents ranging from 1% to 5% (Table 4).

Table 4
Designation of the electrodeposited specimens.

Designation	Coating Combination
AISI 1018 steel	-
NC	(NiSO4·6H2O) + (NiCl2·6H2O) + (H3BO3) + 0% Nano-SiC
NHC1	(NiSO4·6H2O) + (NiCl2·6H2O) + (H3BO3) + 1% Nano-SiC
NHC2	(NiSO4·6H2O) + (NiCl2·6H2O) + (H3BO3) + 2% Nano-SiC
NHC3	(NiSO4·6H2O) + (NiCl2·6H2O) + (H3BO3) + 3% Nano-SiC
NHC4	(NiSO4·6H2O) + (NiCl2·6H2O) + (H3BO3) + 4% Nano-SiC
NHC5	(NiSO4·6H2O) + (NiCl2·6H2O) + (H3BO3) + 5% Nano-SiC

• NC = Nickel Coated on AISI 1018 steel; NHC = Nano Hybrid Coated on AISI 1018 steel

2.3. Hardness analysis

The hardness of the Ni-SiC composite coatings that were applied on AISI 1018 mild carbon steel was evaluated using a Shimadzu micro-Vickers hardness tester (HMV 2T) in accordance with (ASTM E384)³⁰. Samples were cleaned and prepared to ensure a smooth surface, and a 50 g load was applied for 15 seconds during indentation. Multiple measurements were taken at different locations on the coating.

2.4. Corrosion analysis

The salt spray corrosion testing was done under defined conditions to reproduce a corrosive environment following the (ASTM B 117-07)³⁰ standard. The humidity of each room was kept at 98% as indicated by a hygrometer, meaning the atmosphere was very humid. In order to maintain a typical environmental temperature, the temperature was kept between 33 to 35°C. An atomizing regulator was used to regulate air pressure at 2 to 3 bar in order to spray the salt solution consistently. The desired salt solution, consisting of 3.5% sodium chloride (NaCl), 1% magnesium chloride (MgCl₂), and 94% deionized water by weight, was appropriately formulated and employed for the corrosion testing. The pH of the solution was held constant through all the processes at 7.5 and was checked periodically (at 8-hour intervals) to lie in the prescribed pH range. Plastic wire was used to secure the specimens on the testing apparatus and hang in the chamber for even exposure to corrosive conditions during testing. Details such as sample positioning, droplet behavior, and other critical parameters were controlled as per the ASTM standard procedures. Specifically, specimens were hung vertically and spaced to allow uniform exposure to the salt spray, with droplets falling by gravity, ensuring consistent and reproducible exposure.

The salt spray test was used to assess the corrosion resistance of the Ni-SiC composite coatings on AISI 1018 mild carbon steel. Once the specimens were washed and dried, they were inserted into a chamber that sprays salt water. A 5.0–5.3% NaCl solution was used, with controlled conditions of temperature (33.8°C to 34.8°C), pH (6.7 to 7.0), and air pressure (103.421 Pa). After a 720-hour exposure, the specimens were rinsed, dried, and visually inspected for corrosion damage, including pitting and rust formation. The extent of corrosion was recorded, and performance was categorized based on the coating’s resistance to degradation. Minimal corrosion indicated high resistance, while significant corrosion suggested lower effectiveness. Furthermore, the effect of SiC particles on corrosion resistance has been evaluated.

The corrosion rate was calculated based on the material's weight loss over time, and it is given by Equation (1).

$\text{Corrosion Rate}=\frac{\left(\text{k}\times \Delta \text{w}\right)}{\left(\text{A}\times \text{T}\times \rho \right)}$ (1)

Where, A is the exposed surface area of the specimen in cm², ∆w represents the weight loss of the specimen in g, and T is the time of exposure, which is in days depending on the test duration. The density of the material, denoted by ρ, is given in g/cm³. The constant k depends on the units being used, and for corrosion rate calculation in mm/year, a typical value for k is 8.76×10⁴. This equation provides a way to quantify the rate of corrosion by considering the material’s density, exposure area, time, and weight loss during the testing period³².

2.5. Tribological testing

Further, the dry sliding wear test, conducted using the DUCOM pin-on-disc setup as per (ASTM G99)³⁰, evaluates the wear resistance of composite coatings. Cylindrical pins (diameter = 6 mm and length = 8 mm) were cut to prepare specimens of Ni–Nano SiC-coated AISI 1018 mild steel. The pins were cleaned with acetone, then dried and weighed using a digital balance to determine their initial mass. A tribometer was used for performing the test with the specimen kept securely in the pin holder and pressed against a rotating EN32 steel disc of 65 HRC hardness. Throughout the test, the ambient temperature was maintained at 20°C. With a constant normal force of 10 N, a specimen was slid against the disc across a 1000 m sliding distance. The volume of material worn out per unit of stress and sliding distance is determined by Equation (2), which was used to establish the Specific Wear Rate (SWR)³³. The equation is:

$\text{SWR}=\frac{\text{WL}}{\left(\text{L}\times \text{SD}\times \rho \right)}$ (2)

Where WL is the weight loss of the specimen in g, quantifying the total weight lost by the specimen. The composite coating density, which has a unit of g/cm³, denoted by ρ, is important for converting the mass loss to volume loss. L refers to the load acting on the pin in Newtons, which is the normal force applied during the wear test, and SD is the sliding distance in meters, indicating how far the material slides during the test. For X-ray diffraction (XRD) analysis of the Ni-SiC composite coatings, a typical X-ray diffractometer (Rigaku MiniFlex) was used, equipped with monochromatic Cu Kα radiation (wavelength λ = 1.5406 Å). The scan range was set from 20° to 90° (2θ), covering both low-and high-angle diffraction peaks of the nickel (Ni) and SiC phases. To ensure high-resolution data for phase identification and quantitative analysis, a step size of 0.02° (2θ) was chosen, with a scan speed of 0.5°/min to balance resolution and analysis time. The analysis was performed in the θ-2θ configuration, where the X-ray source and detector are positioned symmetrically relative to the sample, allowing for precise and accurate measurement of diffraction angles. The corrosion and worn surfaces were further analyzed using SEM (ZEISS EVO 18 SEM) to examine the morphology and mechanisms of corrosion and wear in the composite coating materials.

3. Results and Discussion

3.1. Microhardness

In this study, the microhardness results show a clear trend of increasing hardness with increasing concentrations of nano-SiC in the nickel matrix. The base material, AISI 1018 steel, exhibited a microhardness of 131 HV and served as the reference for comparison (Figure 2). The pure nickel coating (NC) showed a modest increase to 138 HV, representing a 5.34% improvement over the base steel. This small increase is expected, as electrodeposited nickel coatings tend to be harder than mild steel³⁴. With the incorporation of nano-SiC particles, a progressive enhancement in hardness was observed: NHC1 (1% SiC) reached 156 HV (19.08% increase), NHC2 (2% SiC) 169 HV (29.01%), NHC3 (3% SiC) 182 HV (38.93%), NHC4 (4% SiC) 191 HV (45.80%), and NHC5 (5% SiC) achieved the highest value of 202 HV, corresponding to a 54.20% increase over the uncoated substrate. The promising increase suggests that the nickel deposit, under the given pulse reverse electrodeposition parameters, is not exceptionally hard, possibly due to grain size, residual stresses, or impurities in the coating. As the concentration of nano-SiC in the coating increased, there was a clear enhancement in hardness. The coating's hardness may be greatly enhanced by even tiny amounts of nano-SiC, as shown by this dramatic improvement. This is probably because the SiC particles provide a reinforcement effect, preventing dislocation movement and enhancing the coating's resistance to plastic deformation³⁵. In detail, the primary mechanism driving this improvement is grain refinement, consistent with the Hall-Petch effect. SiC nanoparticles serve as effective nucleation sites, enhancing grain refinement and impeding dislocation motion. Additionally, dispersion strengthening plays a significant role, where the uniformly distributed 45 nm SiC particles obstruct dislocation movement through the formation of Orowan loops, thereby increasing resistance to plastic deformation. As the nano-SiC content increased further, the hardness continued to rise, but the rate of increase gradually diminished. For example, the NHC2 specimen (with 2% SiC) showed an 8.33% increase in hardness, reaching 169 HV. The NHC3 (3% SiC) and NHC4 (4% SiC) specimens demonstrated further increases in hardness but at progressively smaller rates of 7.69% and 4.95%, respectively. By the time the NHC5 specimen (5% SiC) was tested, the hardness reached 202 HV, with a 5.76% increase from the previous specimen, indicating that the incremental benefit of adding more SiC particles was becoming smaller.

Figure 2
Microhardness variation with specimen composition (Ni-Nano SiC coatings on AISI 1018 steel).

This gradual reduction in the rate of hardness improvement can be attributed to several factors. First, as the SiC concentration increases, the dispersion of these particles becomes more challenging. For the reinforcing effect to be maximized, it is vital that the nano-SiC be uniformly distributed throughout the nickel matrix³⁶. At higher concentrations, SiC particles tend to agglomerate detrimentally for their effectiveness in raising the coating strength³⁷. The effectiveness of the SiC particles in transferring load and contributing to the material’s hardness, however, also depends on the bonding strength between the Ni matrix and SiC particles³⁸. These diminishing returns in hardness with increasing SiC content may be explained if the bonding does not lend enough rigidity to realize the full reinforcing effect. The increase in hardness in this study signifies the effective bonding that takes place in the composite coating used for deposition on the AISI 1018 steel. The microstructure of the coating is controlled by the PRED parameters. It is known that the pulse reverse technique can produce fine and refined grain coatings, which yield higher hardness³⁹. However, these parameters also affect the uniformity of SiC particle incorporation and overall deposition rate at the same time.

The chosen parameters, particularly the current density (600 A/m²) and pulse frequency (100 Hz), are within typical ranges for achieving effective coatings, yet variations in these factors can impact grain size and residual stresses in the coating, which, in turn, influence hardness. In conclusion, the microhardness data confirms that incorporating nano-SiC into nickel coatings significantly enhances the hardness, with the most substantial improvements occurring at lower SiC concentrations. However, the benefits tend to plateau at higher SiC content, suggesting that there is an optimal concentration for maximizing hardness. The PRED parameters are crucial in determining the coating's hardness. In this study, the maximum enhancement in hardness was observed for the NHC5 specimen. Accordingly, its XRD spectrum was analyzed and is presented in Figure 3, confirming the presence of both nickel and SiC in the composite coating. The XRD results for pulse reverse electrodeposition of Ni - Nano SiC coatings on AISI 1018 mild steel show key observations related to phase identification, deposition effects, and structural characteristics. The NHC5 XRD pattern retains the characteristic face-centered cubic (FCC) nickel peaks at 2θ values of 44.5° (111), 51.8° (200), and 76.3° (220), with slight peak broadening attributed to grain refinement. Key SiC diffraction peaks were also observed at 35.6° (111), 60.3° (220), and 71.8° (311), corresponding to the cubic β-SiC phase and matching ICDD-PDF Card No. 29-1129. Although the intensity of these SiC peaks is relatively low due to the limited SiC content (5 wt%), their presence confirms successful incorporation of nano-SiC particles into the Ni matrix. Importantly, no intermetallic phases were detected, indicating that the addition of SiC did not alter the interfacial chemistry or lead to undesirable secondary phase formation. The dominant (111) Ni peak suggests that the PRED process preserved the preferred crystallographic orientation of nickel, even with nano-SiC reinforcement. To validate the findings, Figure 4 presents SEM and EDS analyses of the NHC5 specimen, confirming the incorporation of SiC nanoparticles in the coating. Additionally, the XRD pattern of the AISI 1018 steel substrate (Figure 3) reveals a dominant α-Fe (ferrite) phase with a BCC crystal structure. The primary peaks appear at 44.6° (110), 65.0° (200), and 82.3° (211), consistent with ICDD-PDF Card No. 01-087-0721. A minor peak at 37.8°, corresponding to the (121) plane of cementite (Fe₃C), is also present and attributed to the low-carbon content and thermal processing history of the steel. The strong (110) α-Fe reflection confirms the expected BCC ferritic microstructure of untreated AISI 1018 steel. Furthermore, the NC specimen’s XRD pattern, also shown in Figure 3, is dominated by the same FCC nickel peaks at 44.5°, 51.8°, and 76.3° (ICDD-PDF Card No. 04-0850), confirming the successful deposition of Ni through the PRED process. Residual α-Fe peaks from the underlying steel substrate at 44.6°, 65.0°, and 82.3°, along with a faint Fe₃C peak at 37.8°, indicate partial X-ray penetration through the coating. The prominence of the (111) Ni peak further confirms the strong preferred orientation typical of electrodeposited nickel coatings⁴⁰. Notably, no intermetallic compounds were detected, suggesting that interdiffusion between the coating and substrate was minimal under the applied electrodeposition conditions.

Figure 3
XRD graphs of AISI 1018 steel, NC specimen, and NHC5 specimen (Ni-5% Nano SiC coating on AISI 1018 steel).

Figure 4
SEM/EDS analysis of NHC5 specimen (Ni-5% Nano SiC coating on AISI 1018 steel).

3.2. Salt spray corrosion behaviour

In this study, Figures 5 and 6 present the material loss and corrosion rate data from the salt spray corrosion test, comparing AISI 1018 steel and Ni–Nano SiC coatings. Figure 5 illustrates the corrosion rate of the specimens, indicating a significant reduction in corrosion for the Ni-Nano SiC coatings, which exhibit enhanced resistance to salt spray corrosion compared to the bare steel. When compared to the uncoated AISI 1018 steel, the Ni-Nano SiC coatings significantly reduced damage and degradation, as seen in Figure 6, which illustrates the material loss of the specimens following exposure to the salt spray environment. AISI 1018 mild steel, in its uncoated state, is highly vulnerable to corrosion in salt spray environments, as evidenced by a corrosion rate of 0.3191 mm/year and material loss of 0.02064 g. Due to its iron-based composition, the steel surface is directly exposed to the corrosive salt solution, allowing electrochemical reactions to occur. The iron undergoes oxidation, where iron atoms lose electrons and transform into ferrous ions (Fe²⁺), which dissolve into the electrolyte. Oxygen and water in the electrolyte consume the electrons to form hydroxyl ions (OH⁻), leading to the formation of iron oxides (rust) as the ferrous ions react with the hydroxyl ions and oxygen. The chloride ions in the salt solution further accelerate this process, significantly increasing the corrosion rate and causing material degradation⁴¹. The nickel coating on steel, with 0% Nano-SiC, shows a corrosion rate of 0.2060 mm/year and material loss of 0.01334 g, offering an improvement in corrosion resistance compared to the uncoated steel. Nickel, being a more noble metal than iron, has a higher electrochemical potential, and its application as a coating reduces the corrosion rate. However, imperfections or porosity in the coating can still allow some corrosion to occur, though it is significantly lower than that of the uncoated steel.

Figure 5
Corrosion rate of specimens related to steel substrate and coatings.

Figure 6
Material loss of specimens related to steel substrate and coatings.

A physical barrier provided by the Ni coating keeps the steel from coming into contact with the salt solution, which in turn reduces corrosion⁴². Additionally, nickel provides limited galvanic protection, where corrosion is preferentially directed at the iron in areas where the coating has imperfections or pores. The nickel coating also reduces anodic dissolution of iron, further lowering the corrosion rate, but porosity or defects in the coating still lead to localized corrosion at the underlying steel surface.

The Ni-Nano SiC coating with 1% Nano-SiC on AISI 1018 steel shows a corrosion rate of 0.1507 mm/year and material loss of 0.00983 g, demonstrating improved corrosion resistance compared to the uncoated and nickel-coated steel. Nano-SiC particle (1%) addition improves the coating density, reduces porosity, and strengthens the nickel matrix, which provides better protection to the steel substrate. A more uniform and denser barrier to the corrosive salt solution is created due to the nanoparticles, which can reduce the number of potential pathways for electrolyte penetration. The particles also strengthen the nickel matrix to improve its structural integrity so that additional corrosion rate and material loss reduction is achieved⁴³. For NHC2 with 2% nano-SiC, the corrosion rate is 0.1149 mm/year, and material loss equals 0.00763 g. In the higher SiC content, the nickel matrix is strengthened; porosity is reduced, leading to better barrier protection and increased protective life against corrosive environments. Similar to the NHC1, these mechanisms are amplified when the increased nano-SiC concentration leads to a faster corrosion rate and material loss decrease.

The corrosion rate for NHC3 coating (3 wt% Nano-SiC) is 0.0794 mm/year, while the material loss is 0.00533 g. The trend of corrosion resistance improving with a 3% Nano-SiC addition continues. Higher SiC content results in a smoother, more uniform protective layer that is also effective in improving barrier properties and being more resistant to corrosion. Furthermore, the increased nano-SiC content reduces the porosity, resulting in a more compact coating, which decreases the penetration of the corrosive solution, thereby rendering the coating more effective in protecting steel base metal. The corrosion rate of the NHC4 coating with 4% SiC is 0.0393 mm/year, and the material loss is 0.00266 g. The nano-SiC addition of 4% results in a highly effective barrier coating that prevents the corrosion environment from penetrating through with a significant reduction in the corrosion rate and material loss. The increased SiC content toughens the coating and makes it denser and more uniform, resulting in a very dense and robust barrier against corrosion. Nano-SiC particles within the coating are well dispersed and effectively inhibit the corrosive electrolyte from contacting the steel surface, providing the best possible coverage, which slows corrosion attack. In other words, these SiC particles also contribute to reduced porosity by filling gaps and pores, limiting the number of pathways for electrolyte penetration, and reducing localized corrosion at the coating-substrate interface.

NHC5 with 5% Nano-SiC has a 0.0033 mm/year corrosion rate and 0.00223 g material loss, showing the best corrosion resistance of the study. A dense, highly protective coating can be made with the right nano-SiC particle dispersion. As a result, less of the corrosive environment comes into touch with the steel substrate, and the coated surface alone undergoes the opposing chemical reactions. This means that very little material is lost, and corrosion happens very slowly⁴⁴. The continuous barrier thus provides excellent protection and is the result of a uniform distribution of SiC particles. This uniformity in distribution may contribute to enhanced surface characteristics, such as increased compactness and potential hydrophobicity. While the hydrophobic effect was not directly measured in this study, such properties could potentially reduce the adhesion of salt solutions and minimize localized galvanic corrosion by limiting the contact between corrosive agents and the steel substrate. The corrosion resistance of the Ni Nano SiC composite coatings is found to considerably increase with an increase in Nano SiC content. The principal factors that lead to such enhanced performance are the reinforcement effect of the nano-SiC to strengthen the nickel, reduced porosity, and improved barrier protection. The material loss for NHC5 and NHC4 appearing similar—despite the increase in nano-SiC content—can be attributed to a plateau effect or diminishing returns in protective performance. By the time the nano-SiC content reaches 4% in NHC4, the coating likely achieves a highly dense and compact microstructure, effectively minimizing porosity and blocking most pathways for corrosive agents. As a result, further addition of nano-SiC in NHC5 does not substantially enhance the barrier effect because most of the major pores and defects have already been sealed. The observed difference in material loss between NHC4 (0.00266 g) and NHC5 (0.00223 g) is relatively small (~0.00043 g), and this slight variation may fall within the margin of experimental error, especially under salt spray conditions. While the corrosion rate in NHC5 does indicate a slower rate of material degradation per year, the total mass lost remains similar to that of NHC4, possibly due to factors such as test duration, or variations in the initial sample weight. When it comes to developing high-quality coatings with evenly distributed nano-SiC particles, the PRED process is important. The corrosion resistance improves with increasing nano-SiC concentration. The 5% Nano-SiC coating (NHC5) exhibits the best performance, demonstrating optimal protection for AISI 1018 mild steel in salt spray environments.

To better contextualize the corrosion performance of the Ni–SiC coatings developed in this study, comparative data from the literature were reviewed. Electroless Ni–P–15.2 wt% Ti composite coatings on similar steel substrates, for example, exhibited a corrosion rate of 16.7 mm/year, indicating limited resistance in aggressive environments⁴⁵. In contrast, Ni–P–B₄C nanocomposite coatings (1.0 g/L B₄C) showed improved protection, with a corrosion rate of 0.108 mm/year due to enhanced barrier properties⁴⁶. The most advanced corrosion resistance has been reported for organic–inorganic hybrid coatings, such as ZnO/waterborne polyurethane systems, achieving rates as low as 5.759 × 10^-4 mm/year⁴⁷. Although the corrosion rate of the best-performing coating in this study (NHC5, 0.0033 mm/year) does not surpass that of such hybrid systems, it significantly outperforms many conventional metallic and nanocomposite coatings. This underscores the potential of the PRED Ni–nano SiC coatings as a robust, scalable, and cost-effective solution for enhancing corrosion resistance in industrial environments.

3.2.1. Morphology of corrosion surfaces

This work presents the corroded surfaces for several specimens in Figure 7, providing extensive insights into the impact of Ni–Nano SiC composite coatings on enhancing corrosion resistance. The uncoated AISI 1018 steel exhibits a very rough and porous surface, with significant corrosion product formation, including visible pitting. The corrosion products, primarily iron oxides (rust), cover the surface, and localized pitting occurs in specific areas, which can lead to further material degradation over time. The steel undergoes general corrosion, where the surface experiences a uniform attack due to direct exposure to the salt spray, resulting in rust formation. Without a protective barrier, the entire surface is vulnerable to corrosion. Additionally, pitting corrosion occurs in localized spots, where the electrolyte penetrates and causes deeper attacks, leading to material loss (Figure 7 a). These pits exacerbate the corrosion process, compromising the steel’s integrity. The surface-visible iron oxide (rust) is formed when iron combines with oxygen and water, leading to oxide production. The presence of chloride ions from the salt solution accelerates this process, contributing to more rapid rust formation and widespread corrosion.

Figure 7
SEM images of corrosion surfaces of a) AISI 1018 steel, b) NC, c) NHC1, d) NHC2, e) NHC3, f) NHC4, and g) NHC5 specimens.

The nickel coating on the steel surface (NC specimen) provides reduced corrosion compared to the uncoated steel, but some areas still show signs of pitting and surface roughening (Figure 7 b). The coating is not flawless, exhibiting defects such as cracks, voids, or pores that allow the corrosive environment to penetrate and reach the underlying steel, leading to localized corrosion at these points. While the nickel coating offers some protection, these imperfections cause barrier breakdown, allowing the corrosive agents to attack the steel beneath⁴⁸. In regions where the coating is compromised, galvanic corrosion occurred, as the steel and nickel act as two different metals, causing preferential corrosion of the steel at the coating defects. The incorporation of 1% SiC significantly enhances the corrosion resistance of the coating, yielding a smoother surface and a reduction in pits relative to the nickel-only coating. The coating appears more uniform and denser, indicating enhanced protection (Figure 7 c). The improved barrier effect is due to the incorporation of SiC particles, which raise the coating's density and homogeneity, creating a more effective defense against corrosive agents. The corrosion observed in the NHC2 coating shows noticeable improvement, with a smoother surface and less severe corrosion compared to previous coatings (Figure 7 d). The coating is more uniform and denser. With 2% Nano-SiC, the barrier effect is increased because it strengthens the protective layer of coating, hence making it harder for corrosive elements to penetrate. The better microstructure of the coating results from the more uniform distribution of SiC particles, which diminishes defect development, hence enhancing the protection of the steel substrate and significantly lowering the risk of localized corrosion. However, the NHC3 coating still shows improvement in corrosion resistance compared to NHC2 (Figure 7 e). The inclusion of 3% SiC significantly improves the barrier effect since this nano oxide, despite its little quantity, boosts the coating's density and inhibits the infiltration of corrosive substances, hence augmenting the coating's protective characteristics. Furthermore, the increased SiC content will realize the potential hydrophobic properties of the coating, which will minimize the adhesion of the electrolyte (salt solution) on the surface⁴⁹. In addition, this method of reducing moisture exposure also significantly reduces the chance of corrosion.

When coating is added at 4% Nano-SiC to the coating, the corrosion reduces drastically (Figure 7 f), and the surface is smooth with minimum (if any) corrosion. The coating is highly uniform and dense, providing an excellent barrier against the corrosive environment. The higher percentage of nano-SiC particles inside the coating creates a robust protective structure, effectively preventing the corrosive electrolyte from reaching the steel substrate. Furthermore, the minimal pitting observed is owing to the homogeneous dispersion of SiC particles, which greatly reduces localized corrosion, particularly pitting, leading to a significant minimization of overall corrosion damage. SiC agglomeration has different effects on hardness and corrosion resistance. For hardness, uniform nano-SiC dispersion is crucial to impede dislocation motion, but agglomeration at higher concentrations reduces reinforcement efficiency. For corrosion resistance, agglomerated SiC particles can still enhance performance by filling pores and acting as a physical barrier, aiding in corrosion protection despite undermining mechanical strengthening. Nano-SiC increases hardness and creates a more uniform coating, limiting corrosive electrolyte penetration and improving corrosion resistance. While higher hardness may suggest a more robust structure, it is not the only factor improving corrosion performance. NHC5 exhibits the best corrosion resistance, with an almost flawless surface showing minimal corrosion. The coating is dense and nearly impervious to the corrosive environment, providing optimal protection (Figure 7 g). The 5% Nano-SiC content ensures the SiC particles are well-dispersed throughout the coating, forming a continuous, dense, and highly protective barrier, resulting in extremely low corrosion rates and minimal material loss. The dense and uniform coating significantly reduces the porosity, preventing any electrolyte from penetrating the steel surface, offering exceptional corrosion protection, and reducing corrosion pathways. Additionally, the minimization of galvanic corrosion is achieved by the uniform distribution of nano-SiC particles, avoiding direct interaction between the steel substrate and corrosive substances, ensuring more uniform protection across the surface.

The SEM images show that the corrosion resistance of Ni coatings improves with increasing nano-SiC concentration. Coatings improve in density, uniformity, and corrosion resistance as the SiC concentration rises. The coatings act as effective barriers, with the SiC particles helping to fill in pores and reduce pathways for electrolyte penetration. The images show a marked reduction in corrosion damage, particularly in the NHC4 and NHC5 coatings, which exhibit the best protection with minimal corrosion and surface damage. In conclusion, the SEM images and corrosion mechanisms clearly demonstrate that nano-SiC significantly enhances the protective properties of the Ni coatings. A stronger and more effective defence against corrosive conditions is provided by the presence of SiC particles, which, as the SiC concentration rises, leads to improved corrosion resistance.

The notable enhancement in corrosion resistance shown in the Ni-SiC composite coatings, especially in NHC5 with 5% SiC, is mostly ascribed to the synergistic effects of galvanic mitigation and barrier protection. NHC5 demonstrated a remarkable reduction in corrosion rate, representing a 99% decrease compared to the uncoated AISI 1018 steel. This enhancement is largely due to the barrier effect, whereby nano-sized SiC particles efficiently occupy the micro-pores and voids within the Ni matrix. This densification limits the penetration of corrosive electrolytes, thereby reducing the pathways available for corrosion initiation. SEM analysis further confirms a significant reduction in porosity and minimal pitting in the NHC5 coating. Adding SiC also aids in galvanic mitigation because, as an electrical insulator, it disrupts the galvanic coupling between the Ni coating and the Fe substrate, thereby reducing the extent of galvanic corrosion. These synergistic effects result in superior corrosion resistance across the Ni-SiC coated specimens, with NHC5 showing the most pronounced improvement.

The differing effects of SiC agglomeration on hardness and corrosion resistance arise from distinct underlying mechanisms. Hardness enhancement relies on the Orowan mechanism, where uniformly dispersed nanoparticles effectively pin dislocations; agglomeration reduces this efficiency by creating particle-free zones that permit easier dislocation motion. In contrast, corrosion resistance is primarily improved through physical barrier effects—agglomerated SiC particles, despite being less effective for strengthening, still fill micro-pores and obstruct electrolyte pathways. SEM analysis confirms that these agglomerates occupy pore sites that would otherwise promote pitting. As a result, the 5% SiC coating, though showing a modest compromise in hardness (202 HV, a 46% increase over base Ni), achieves a 98.4% reduction in corrosion rate—highlighting that the protective benefits of agglomeration for corrosion resistance outweigh its minor impact on mechanical reinforcement.

3.3. Dry sliding wear behaviour

In this study, Figures 8 and 9 provide insights into the wear behavior of the steel substrate and composite coatings under dry sliding conditions, highlighting the improved wear resistance provided by the composite coatings. Taken as a whole, these figures reveal that, particularly at higher nano-SiC concentrations, wear resistance and friction are both markedly enhanced by adding nano-SiC to Ni coatings. As the baseline material, AISI 1018 steel exhibits the highest Specific Wear Rate (SWR) and Coefficient of Friction (COF), highlighting its relatively poor wear resistance and frictional properties. With a hardness of 131 HV, the steel is relatively soft, which contributes to its higher wear rate. This serves as the benchmark for assessing the improvements achieved by the Ni-Nano SiC coatings. The pure nickel coating (NC) provides a noticeable improvement over the baseline material. It shows an 18.94% decrease in SWR and a 14.04% reduction in COF, indicating enhanced wear resistance and lower friction. The hardness of the NC specimen is slightly higher (138 HV) compared to the AISI 1018 steel, which likely contributes to the observed improvements. The pure nickel coating, while not containing any nano-SiC, still enhances the substrate's tribological properties due to its relatively higher hardness and smooth surface.

Figure 8
Specific wear rate of specimens related to AISI 1018 steel and Ni-Nano SiC coatings.

Figure 9
COF of specimens related to steel substrate and coatings.

The NHC series demonstrates a clear relationship between the increase in hardness and the corresponding improvements in SWR and COF. Coating hardness and tribological performance are both enhanced with increasing nano-SiC concentration. The addition of 1% Nano-SiC shows a substantial improvement in both wear resistance and friction reduction. The SWR decreases by 44.17%, and the COF reduces by 35.47%. These improvements are partly due to the increase in coating hardness to 156 HV. The incorporation of nano-SiC particles reinforces the nickel matrix, thereby enhancing its wear resistance⁵⁰. At 2% Nano-SiC, further improvements are observed, with a 59.85% reduction in SWR. At 2% Nano-SiC, further improvements are observed, with a 59.85% reduction in SWR. However, the COF reduction (33.87%) is slightly lower than that of NHC1 (35.47%). While the specific reasons for this variation are not confirmed in this study, factors such as surface roughness or microstructural differences may influence the frictional behavior and warrant further investigation. The hardness increases to 169 HV, further enhancing the wear resistance. This suggests that the increasing hardness continues to improve wear resistance, although the impact on COF may be influenced by other factors.

With 3% Nano-SiC, both SWR and COF show continued improvement, with reductions of 73.37% and 46.80%, respectively. The hardness increases to 182 HV, indicating a further strengthening of the coating. This continued trend demonstrates that higher SiC concentrations improve both wear resistance and friction performance, reinforcing the positive correlation between hardness and tribological properties. At 4% Nano-SiC, significant improvements are achieved, with an 85.49% reduction in SWR and a 59% reduction in COF. The hardness increases substantially to 191 HV, highlighting the correlation between wear performance and hardness. The continued improvement in both wear and friction is evident, showcasing the effectiveness of incorporating nano-SiC particles into the coating. The NHC5 specimen, with the highest concentration of nano-SiC, shows the best performance, with a 93.12% reduction in SWR and a 62.93% reduction in COF. The maximum value for wear resistance and friction reduction is shown by the greatest hardness curve at 202 HV. With clearly indicating that boosting the content of nano-SiC, besides the enhancement of hardness, also the tribological performance of the coating is remarkably enhanced. The tribological performance of the coating, which is progressively reduced in terms of SWR and COF with increasing hardness, is positively correlated with the hardness of the coating⁵¹. However, nano-SiC particle addition is of major significance in enhancing coating hardness and its wear resistance, as well as its frictional properties. Continuous improvement in the performance with the increase in nano-SiC concentration is clear evidence of this statement. The crucial factor that determines the wear resistance for the coating is the hardness. Thus, coatings with higher hardness are more resistant to wear and have lower friction. Hardness, SWR reduction, and COF reduction trends are the same across the NHC series, demonstrating that the Ni-Nano SiC coatings indeed improve the tribological performance. The incorporation of hardness into the analysis yields some very useful information regarding the performance of coatings. The data clearly shows that adding nano-SiC to the composite coating made it harder, which made it more resistant to wear and better at reducing friction. It is evident that the Ni-Nano SiC composite coatings possess improvements in both mechanical and tribological properties, and accordingly, NHC5 has higher hardness and nano-SiC contents than the other specimens. These results indicate clearly that for enhancing tribological properties, reinforcing materials are very important in order to reduce friction and to improve the wear resistance of the Ni-based coatings. The results for NHC5 (5% Nano-SiC) clearly demonstrate that nano-SiC particles are an effective means of enhancing the wear properties of nickel matrix coatings. Finally, the PRED technique is essential for optimizing the coating properties and uniform dispersing of nano-SiC particles⁵². The incorporation of hard particles, such as ceramic particles like SiC, into coatings improves their performance, as demonstrated in this study, particularly in situations requiring low friction and excellent wear resistance. Several key factors influence the COF in Ni-SiC composite coatings, each contributing to the observed performance trends. Increased hardness generally leads to minimal COF by minimizing surface deformation during sliding, as evidenced by NHC5—the hardest specimen—exhibiting the lowest COF. The dispersion of SiC particles also plays a critical role; uniform distribution facilitates the formation of a smoother, more continuous tribolayer, which reduces friction. In this regard, NHC1, with better dispersion, outperformed NHC2, where particle clustering led to uneven surfaces. Surface roughness is another major contributor, with increased roughness promoting greater asperity contact and, consequently, higher COF. This was apparent in NHC2, which displayed a rougher surface compared to NHC1. Additionally, the formation of a SiC-rich tribofilm helps lower COF by reducing adhesive interactions at the sliding interface, with optimal tribofilm development observed in coatings containing 3–5% SiC. Lastly, the dominant wear mechanism influences COF; abrasive wear, which tends to increase friction, was more prominent in NHC2, whereas coatings exhibiting adhesive wear typically showed lower COF values. These combined effects explain the nuanced variations in frictional behavior across the Ni-SiC coating series.

3.3.1. Worn surfaces morphology

In this investigation, increasing the nano-SiC content in the composite coatings enhanced wear resistance, as evidenced by the worn surface micrographs of the specimens (Figure 10). All images display characteristic wear features such as debris, grooves, and scratches, indicating that adhesive and abrasive wear mechanisms are at play. However, the intensity and distribution of these features vary across the different specimens, reflecting the varying effectiveness of the coatings in reducing wear. The uncoated AISI 1018 steel exhibits a rough surface marked by deep grooves and scratches (Figure 10 a), which are characteristic of combined abrasive and adhesive wear mechanisms. In contrast, the smoother worn surface of the NHC5 coating highlights the effective wear-reducing role of nano-SiC reinforcement (Figure 10 g). These features suggest the dominance of abrasive wear, where scratching and material removal occur, and adhesive wear, where material transfer occurs due to micro-welding and shearing between the sliding surfaces. The rough surface is indicative of significant plastic deformation, typical of softer materials like AISI 1018 steel. The nickel coating (NC - 0% Nano-SiC) shows reduced wear compared to the uncoated steel, with fewer deep grooves and scratches. The surface is smoother, and although some abrasive wear and adhesive wear are still observed, the damage is less severe than that of the uncoated steel (Figure 10 b). The nickel coating, being harder than the steel, offers better resistance to abrasion, and its smoother surface reduces material transfer, but some wear is still present due to the absence of additional reinforcement. As the nano-SiC content increases in the Ni-Nano SiC coatings, the wear resistance progressively improves. For NHC1 (1% Nano-SiC), the SEM image shows fewer and less pronounced grooves and scratches, with a smoother surface (Figure 10 c). The abrasive wear is further reduced as the nano-SiC particles begin to reinforce the nickel matrix⁵³. These particles start to contribute to load-bearing, protecting the softer nickel matrix and reducing the overall wear. In NHC2 (2% Nano-SiC), the wear features are even less severe, and the surface is noticeably smoother (Figure 10 d).

Figure 10
Worn surfaces of a) AISI 1018 steel, b) NC, c) NHC1, d) NHC2, e) NHC3, f) NHC4, and g) NHC5 specimens.

The higher content of nano-SiC further reduces abrasive wear and improves the load-bearing capacity, with more SiC particles sharing the applied load. This results in a significant reduction in material deformation and wear. It is to be noted that the unexpected increase in the COF for NHC2—showing only a 33.87% reduction compared to 35.47% for NHC1—can be attributed to several interrelated factors. At 2% SiC content, particle clustering likely contributed to increased microscale surface roughness, resulting in more asperity contact and elevated friction levels. This is supported by SEM images (Figures 9 c and d), which reveal mild plowing grooves in NHC2, indicative of abrasive interactions. Additionally, NHC1, with 1% SiC, may have formed a more uniform and stable SiC-rich tribolayer that effectively reduced adhesive wear. In contrast, NHC2’s intermediate SiC concentration might have been insufficient to establish a consistent tribofilm, limiting its friction-reducing potential. Furthermore, the wear mechanism appears to transition at this stage; while NHC1 predominantly resisted adhesive wear, the increased hardness in NHC2 may have shifted the wear mode toward abrasion, which can initially increase COF until higher SiC levels (as seen in NHC3 and beyond) optimize surface protection and tribological behavior. For NHC3 (3% Nano-SiC), the wear resistance continues to improve, with even fewer wear features visible on the surface (Figure 10 e). The abrasive wear is minimized, and the microstructural refinement introduced by the additional SiC content enhances the hardness and wear resistance of the coating. NHC4 (4% Nano-SiC) shows a remarkable reduction in wear damage, with a relatively smooth surface and minimal visible wear features (Figure 10 f). The abrasive wear is minimal, and the SiC particles are highly effective in bearing the applied load, effectively protecting the nickel matrix from excessive wear. Finally, NHC5 (5% Nano-SiC) demonstrates the best wear performance, with the smoothest surface and very few visible wear features. The abrasive wear is almost negligible, and the SiC particles provide optimal reinforcement, further improving the wear resistance (Figure 10 g). The reduced friction and minimal wear observed in the NHC5 coating may also be attributed to the potential lubricating effect of SiC particles. In summary, the microscopic images confirm that the wear resistance of the Ni–nano SiC composite coatings significantly improve with increasing nano-SiC content. The progressive reduction in both abrasive and adhesive wear highlights the importance of incorporating hard SiC particles to reinforce the nickel matrix, distribute the load, and reduce material deformation. NHC5, with 5% Nano-SiC, exhibits the best tribological performance, confirming that the optimal dispersion of SiC particles leads to maximum reinforcement and minimal wear. This demonstrates the effectiveness of the coatings in enhancing the wear resistance of AISI 1018 steel.

The exceptional wear resistance exhibited by the composite coating—particularly in the NHC5 specimen containing 5% SiC—likely results from reinforcing tribological mechanisms. An important consideration is the enhanced load-bearing capacity imparted by the nano-SiC particles, which share the applied load and reduce plastic deformation of the Ni matrix. Further evidence that wear-induced SiC debris helps form a protective tribofilm on the contact surface, thereby reducing direct metal-to-metal contact, is provided by the smoother wear tracks observed in NHC5. Furthermore, the intrinsic self-lubricating properties of SiC at the nanoscale help to suppress adhesive wear mechanisms, contributing to the reduced COF, which drops to 0.21 for NHC5. These synergistic effects collectively account for the substantial enhancement in wear resistance across the Ni-SiC coated specimens.

4. Conclusions

This research focused on systematically varying the concentration of nano-SiC (1%, 2%, 3%, 4%, and 5%) to enhance the properties of Ni-SiC composite coatings on AISI 1018 steel via the Pulse Reverse Electrodeposition (PRED) method. Specimens such as Nickel Coated on AISI 1018 steel (NC) and Nano Hybrid Coated on AISI 1018 steels (NHC1-NHC5) were developed, and their hardness, corrosion, and wear behaviours were observed and compared with AISI 1018 steel. The major findings are as follows:

• The Ni-nano SiC composite coatings significantly improve the hardness, tribological, and corrosion resistance properties of AISI 1018 steel. The enhancement is most pronounced at a 5% nano-SiC concentration, which yielded the best overall performance across all evaluated metrics.

• The inclusion of nano-SiC particles plays a critical role in reinforcing the Ni matrix. Even at a low concentration (1%), SiC particles enhance hardness, while higher concentrations (up to 5%) provide a denser and more uniform microstructure. This contributes to a marked improvement in microhardness, wear resistance, and friction reduction. Moreover, the nanoparticles act as effective barriers against corrosive agents, reducing corrosion rates dramatically by forming a compact and protective surface layer.

• XRD analysis confirmed that the coatings consist predominantly of metallic nickel, with embedded SiC particles that maintain their crystalline identity. The primary diffraction peaks of Ni and secondary peaks of SiC support the successful co-deposition and structural integrity of both constituents within the coating.

• While increasing nano-SiC content leads to improvements in coating performance, the results also suggest diminishing returns beyond certain concentrations. The most substantial gains in hardness and wear resistance occur between 1% and 5% SiC, implying an optimal range for particle loading without unnecessarily increasing material costs or complexity.

• The enhanced Ni–nano SiC composite coatings developed in this study are well-suited for applications requiring moderate surface durability, improved wear resistance, and enhanced corrosion protection under low-to-medium load conditions. Potential use cases include selected automotive components (e.g., brackets, fasteners, hydraulic parts), marine hardware (e.g., pump shafts, valve housings), and general-purpose industrial equipment exposed to abrasive or corrosive environments. For high-load or critical applications—such as cutting tools, gears, or turbine components—where hardness values exceeding 500 HV are typically required, further optimization through post-deposition heat treatment, the use of harder matrix alloys (e.g., Ni–P or Ni–B), or increased ceramic reinforcement may be necessary. Nonetheless, the coatings presented here offer a cost-effective solution for extending the service life of mild steel components in non-critical or moderately abrasive environments.

• In summary, nano-SiC reinforced nickel coatings offer a cost-effective and efficient strategy to significantly extend the service life of steel components, demonstrating promising potential for widespread industrial use.

• Data Availability
  The entire dataset supporting the results of this study was published in the article itself.

5. References

• ¹ Kumar A, Pankaj P, Biswas P, Rao AG. Finite element analysis and experimental investigation on effect of process parameters in plasma-assisted friction stir welding of low carbon steel. Trans Indian Inst Met. 2022;75(10):2559-79. https://doi.org/10.1007/s12666-022-02624-3
  » https://doi.org/10.1007/s12666-022-02624-3
• ² Khan R, Ya H, Pao W. An experimental study on the erosion-corrosion performance of AISI 1018 carbon steel and AISI 304L stainless steel 90-degree elbow pipe. Metals. 2019;9(12):1260. https://doi.org/10.3390/met9121260
  » https://doi.org/10.3390/met9121260
• ³ Butley SD, Dhole LP, Chavhan GR. Tribological behavior of low carbon steel, grade AISI1018 overlayed with nickel based MMC plus WC. J Phys Conf Ser. 2024;2763(1):012009. https://doi.org/10.1088/1742-6596/2763/1/012009
  » https://doi.org/10.1088/1742-6596/2763/1/012009
• ⁴ Jegan A, Venkatesan R, Arunachalam R. Mechanical properties of Ni-nano-Al2O3 composite coatings on AISI 304 stainless steel by pulsed electrodeposition. Sci Eng Compos Mater. 2014;21(3):351-8. https://doi.org/10.1515/secm-2013-0071
  » https://doi.org/10.1515/secm-2013-0071
• ⁵ Liu C, Huang X, Xu R, Mai Y, Zhang L, Jie X. Microstructure and properties of nanocrystalline Ni-Mo coatings prepared by ultrasound-assisted pulse electrodeposition. J Mater Eng Perform. 2021;30(4):2514-25. https://doi.org/10.1007/s11665-021-05570-1
  » https://doi.org/10.1007/s11665-021-05570-1
• ⁶ Majidi H, Aliofkhazraei M, Karimzadeh A, Rouhaghdam AS. Corrosion and wear behaviour of multilayer pulse electrodeposited Ni–Al 2 O 3 nanocomposite coatings assisted with ultrasound. Bull Mater Sci. 2016;39(7):1691-9. https://doi.org/10.1007/s12034-016-1307-7
  » https://doi.org/10.1007/s12034-016-1307-7
• ⁷ Akhtar K, Khan ZU, Gul M, Zubair N, Shah SSA. Electrodeposition and characterization of Ni-Al 2 O 3 nanocomposite coatings on steel. J Mater Eng Perform. 2018;27(6):2827-37. https://doi.org/10.1007/s11665-018-3346-2
  » https://doi.org/10.1007/s11665-018-3346-2
• ⁸ Suresh V, Jegan A. Experimental studies on wear and corrosion resistance of pulse electrodeposited Ni-TiO2 nanocomposite coatings on AISI 304 stainless steel. Mater Res Express. 2022;9(12):126401. https://doi.org/10.1088/2053-1591/acabb2
  » https://doi.org/10.1088/2053-1591/acabb2
• ⁹ Li C, Wang Y, Pan Z. Wear resistance enhancement of electroless nanocomposite coatings via incorporation of alumina nanoparticles prepared by milling. Mater Des. 2013;47:443-8. https://doi.org/10.1016/j.matdes.2012.12.021
  » https://doi.org/10.1016/j.matdes.2012.12.021
• ¹⁰ Gupta A, Barkam S, Lahiri D, Balasubramaniam R, Balani K. Effect of alumina dispersion on microstructural and nanomechanical properties of pulse electrodeposited nickel–alumina composite coatings. J Mater Sci Technol. 2014;30(8):808-13. https://doi.org/10.1016/j.jmst.2013.12.013
  » https://doi.org/10.1016/j.jmst.2013.12.013
• ¹¹ Gao M, Pei Z, Song G, Liu Z, Li H, Gong J. Wear resistance of Ni/nano-Al2O3 composite coatings by brush electroplating. J Mater Sci. 2024;59(16):7009-27. https://doi.org/10.1007/s10853-024-09563-y
  » https://doi.org/10.1007/s10853-024-09563-y
• ¹² Li Z, Farhat Z. The effect of the formation of superelastic NiTi phase on static and dynamic corrosion Performance of Ni-P coating. Solids. 2021;2(3):278-92. https://doi.org/10.3390/solids2030018
  » https://doi.org/10.3390/solids2030018
• ¹³ Li Y, Zhang K, Zhang M, Zhang Y, Wu T, Zhao H, et al. Preparation of sol‐enhanced Ni–P–Al2O3 nanocomposite coating by electrodeposition. J Nanomater. 2020;2020(1):5239474. https://doi.org/10.1155/2020/5239474
  » https://doi.org/10.1155/2020/5239474
• ¹⁴ Raghavendra CR, Basavarajappa S, Sogalad I. Optimization of wear parameters on Ni–Al2O3 nanocomposite coating by electrodeposition process. SN Appl Sci. 2019;1(1):131. https://doi.org/10.1007/s42452-018-0135-3
  » https://doi.org/10.1007/s42452-018-0135-3
• ¹⁵ Jensen R, Farhat Z, Islam MA, Jarjoura G. Erosion–corrosion of novel electroless Ni-P-NiTi composite coating. Corros Mater Degrad. 2023;4(1):120-41. https://doi.org/10.3390/cmd4010008
  » https://doi.org/10.3390/cmd4010008
• ¹⁶ Rana ARK, Islam MA, Farhat Z. Effect of Graphene Nanoplatelets (GNPs) addition on erosion–corrosion resistance of electroless Ni–P coatings. J Bio Tribocorros. 2020;6(1):11. https://doi.org/10.1007/s40735-019-0304-y
  » https://doi.org/10.1007/s40735-019-0304-y
• ¹⁷ Tamilarasan TR, Sanjith U, Rajendran R, Rajagopal G, Sudagar J. Effect of reduced graphene oxide reinforcement on the wear characteristics of electroless Ni-P coatings. J Mater Eng Perform. 2018;27(6):3044-53. https://doi.org/10.1007/s11665-018-3246-5
  » https://doi.org/10.1007/s11665-018-3246-5
• ¹⁸ Hyie KM, Zabri MZ, Roseley NRN, Masdek NRNM. Effect of deposition time on wear and corrosion performance of Co–Ni–Fe alloy coated mild steel. J Mater Res. 2016;31(13):1848-56. https://doi.org/10.1557/jmr.2016.32
  » https://doi.org/10.1557/jmr.2016.32
• ¹⁹ Sohrabi A, Dolati A, Ghorbani M, Monfared A, Stroeve P. Nanomechanical properties of functionally graded composite coatings: electrodeposited nickel dispersions containing silicon micro-and nanoparticles. Mater Chem Phys. 2010;121(3):497-505. https://doi.org/10.1016/j.matchemphys.2010.02.014
  » https://doi.org/10.1016/j.matchemphys.2010.02.014
• ²⁰ Rao H, Li W, Zhao F, Song Y, Liu H, Zhu L, et al. Electrodeposition of high-quality Ni/SiC composite coatings by using binary non-ionic surfactants. Molecules. 2023;28(8):3344. https://doi.org/10.3390/molecules28083344
  » https://doi.org/10.3390/molecules28083344
• ²¹ Bajwa RS, Khan Z, Bakolas V, Braun W. Water-lubricated Ni-based composite (Ni–Al2O3, Ni–SiC and Ni–ZrO2) thin film coatings for industrial applications. Acta Metall Sin. 2016;29(1):8-16. https://doi.org/10.1007/s40195-015-0354-1
  » https://doi.org/10.1007/s40195-015-0354-1
• ²² Wang P, Cheng YL, Zhang Z. A study on the electrocodeposition processes and properties of Ni–SiC nanocomposite coatings. J Coat Technol Res. 2011;8(3):409-17. https://doi.org/10.1007/s11998-010-9310-1
  » https://doi.org/10.1007/s11998-010-9310-1
• ²³ Yang Y, Cheng YF. Fabrication of Ni–Co–SiC composite coatings by pulse electrodeposition: effects of duty cycle and pulse frequency. Surf Coat Tech. 2013;216:282-8. https://doi.org/10.1016/j.surfcoat.2012.11.059
  » https://doi.org/10.1016/j.surfcoat.2012.11.059
• ²⁴ Tian ZJ, Wang DS, Wang GF, Shen LD, Liu ZD, Huang YH. Microstructure and properties of nanocrystalline nickel coatings prepared by pulse jet electrodeposition. Trans Nonferrous Met Soc China. 2010;20(6):1037-42. https://doi.org/10.1016/S1003-6326(09)60254-5
  » https://doi.org/10.1016/S1003-6326(09)60254-5
• ²⁵ Shathish Kumar JS, Jegan A. Assessment on the microhardness and corrosion resistance characteristics of Ni-SiC and Ni-MWCNT coatings by pulse reverse electrodeposition technique. Mater Res Express. 2020;7(5):055012. https://doi.org/10.1088/2053-1591/ab8e6e
  » https://doi.org/10.1088/2053-1591/ab8e6e
• ²⁶ Xu YH, Liu SL, Liu XW. Wear resistance of high frequency pulse electroplating Ni-SiC nano-composite coating. Adv Mat Res. 2012;465:61-5. https://doi.org/10.4028/www.scientific.net/AMR.465.61
  » https://doi.org/10.4028/www.scientific.net/AMR.465.61
• ²⁷ Natarajan P, Periyasamy M, Jamuna R, Sakunthala K, Mohanraj M. Optimization of electrodeposition parameters to maximize the microhardness of Ni-SiC nanocomposite coatings using RSM. Mater Today Proc. 2023. In press. https://doi.org/10.1016/j.matpr.2023.03.419
  » https://doi.org/10.1016/j.matpr.2023.03.419
• ²⁸ Ma C, He H, Zhang H, Xia F, Li H. Impact of ultrasonic power density on the structure and performance of Ni-W-SiC composite nanocoatings. Surf Coat Tech. 2025;496:131641. https://doi.org/10.1016/j.surfcoat.2024.131641
  » https://doi.org/10.1016/j.surfcoat.2024.131641
• ²⁹ Lee HK, Lee HY, Jeon JM. Codeposition of micro-and nano-sized SiC particles in the nickel matrix composite coatings obtained by electroplating. Surf Coat Tech. 2007;201(8):4711-7. https://doi.org/10.1016/j.surfcoat.2006.10.004
  » https://doi.org/10.1016/j.surfcoat.2006.10.004
• ³⁰ Guthrie RIL, Jonas J. Steel processing technology. In: ASM Handbook Committee, editor. Properties and selection: irons steels and high-performance alloys. Almere: ASM International; 1990. https://doi.org/10.31399/asm.hb.v01.a0001007
  » https://doi.org/10.31399/asm.hb.v01.a0001007
• ³¹ Ahmed MM, Jouini N, Alzahrani B, Seleman MMES, Jhaheen M. Dissimilar friction stir welding of AA2024 and AISI 1018: microstructure and mechanical properties. Metals. 2021;11(2):330. https://doi.org/10.3390/met11020330
  » https://doi.org/10.3390/met11020330
• ³² Malaret F, Yang XS. Exact calculation of corrosion rates by the weight-loss method. Exp Results. 2022;3:e13. https://doi.org/10.1017/exp.2022.5
  » https://doi.org/10.1017/exp.2022.5
• ³³ Jatti VS, Krishnan RM, Saiyathibrahim A, Preethi V, Kumar A, Sharma S, et al. Predicting specific wear rate of laser powder bed fusion AlSi10Mg parts at elevated temperatures using machine learning regression algorithm: unveiling of microstructural morphology analysis. J Mater Res Technol. 2024;33:3684-95. https://doi.org/10.1016/j.jmrt.2024.09.244
  » https://doi.org/10.1016/j.jmrt.2024.09.244
• ³⁴ Haq IU, Akhtar K, Khan TI, Shah AA. Electrodeposition of Ni–Fe2O3 nanocomposite coating on steel. Surf Coat Tech. 2013;235:691-8. https://doi.org/10.1016/j.surfcoat.2013.08.048
  » https://doi.org/10.1016/j.surfcoat.2013.08.048
• ³⁵ Pinate S, Ghassemali E, Zanella C. Strengthening mechanisms and wear behavior of electrodeposited Ni–SiC nanocomposite coatings. J Mater Sci. 2022;57(35):16632-48. https://doi.org/10.1007/s10853-022-07655-1
  » https://doi.org/10.1007/s10853-022-07655-1
• ³⁶ Zhu Z, Ning W, Niu X, Zhao Y. Machine learning-based research on tensile strength of SiC-reinforced magnesium matrix composites via stir casting. Acta Metall Sin. 2024;37(3):453-66. https://doi.org/10.1007/s40195-024-01673-5
  » https://doi.org/10.1007/s40195-024-01673-5
• ³⁷ Grosjean A, Rezrazi M, Takadoum J, Berçot P. Hardness, friction and wear characteristics of nickel-SiC electroless composite deposits. Surf Coat Tech. 2001;137(1):92-6. https://doi.org/10.1016/S0257-8972(00)01088-4
  » https://doi.org/10.1016/S0257-8972(00)01088-4
• ³⁸ Jarząbek DM, Dziekoński C, Dera W, Chrzanowska J, Wojciechowski T. Influence of Cu coating of SiC particles on mechanical properties of Ni/SiC co-electrodeposited composites. Ceram Int. 2018;44(17):21750-8. https://doi.org/10.1016/j.ceramint.2018.08.271
  » https://doi.org/10.1016/j.ceramint.2018.08.271
• ³⁹ Akbarpour MR, Asl FG, Rashedi H. Pulse-reverse electrodeposition of Ni-Co/graphene composite films with high hardness and electrochemical behaviour. Diamond Related Materials. 2023;133:109720. https://doi.org/10.1016/j.diamond.2023.109720
  » https://doi.org/10.1016/j.diamond.2023.109720
• ⁴⁰ Yan T, Huang YC, Hou YC, Chang L. Epitaxial growth and microstructural evolution of nickel electrodeposited on a polycrystalline copper substrate. J Electrochem Soc. 2018;165(14):D743-52. https://doi.org/10.1149/2.0831814jes
  » https://doi.org/10.1149/2.0831814jes
• ⁴¹ Martin U, Bastidas DM. Stress corrosion cracking failure analysis of AISI 1018 carbon steel reinforcing bars in carbonated and chloride contaminated environment. Eng Fail Anal. 2023;147:107159. https://doi.org/10.1016/j.engfailanal.2023.107159
  » https://doi.org/10.1016/j.engfailanal.2023.107159
• ⁴² Khorsand S, Raeissi K, Ashrafizadeh F. Corrosion resistance and long-term durability of super-hydrophobic nickel film prepared by electrodeposition process. Appl Surf Sci. 2014;305:498-505. https://doi.org/10.1016/j.apsusc.2014.03.123
  » https://doi.org/10.1016/j.apsusc.2014.03.123
• ⁴³ Priyadarshi P, Katiyar PK, Maurya R. A review on mechanical, tribological and electrochemical performance of ceramic particle-reinforced Ni-based electrodeposited composite coatings. J Mater Sci. 2022;57(41):19179-211. https://doi.org/10.1007/s10853-022-07809-1
  » https://doi.org/10.1007/s10853-022-07809-1
• ⁴⁴ Kurtuluş V, Görgülü B, Eraslan FS, Gecu R. Improving wear and corrosion resistance of Ti-alloyed nodular cast irons by Al₂O₃ and SiC-reinforced Al₂O₃ coatings. Surf Coat Tech. 2025;498:131809. https://doi.org/10.1016/j.surfcoat.2025.131809
  » https://doi.org/10.1016/j.surfcoat.2025.131809
• ⁴⁵ Li Z, Islam A, Farhat Z. Investigation of erosion–corrosion resistance of electroless Ni–P–Ti composite coatings. J Bio Tribocorros. 2020;6(4):107. https://doi.org/10.1007/s40735-020-00404-4
  » https://doi.org/10.1007/s40735-020-00404-4
• ⁴⁶ Fayyaz O, Yusuf MM, Bagherifard S, Montemor MF, Shakoor RA. Probing into the properties of B4C reinforced nickel phosphorus-based nanocomposite coating. J Mater Res Technol. 2022;20:2323-34. https://doi.org/10.1016/j.jmrt.2022.07.184
  » https://doi.org/10.1016/j.jmrt.2022.07.184
• ⁴⁷ Salazar-Bravo P, Del Angel-López D, Torres-Huerta AM, Domínguez-Crespo MA, Palma-Ramírez D, Brachetti-Sibaja SB, et al. Investigation of ZnO/waterborne polyurethane hybrid coatings for corrosion protection of AISI 1018 carbon steel substrates. Metall Mater Trans, A Phys Metall Mater Sci. 2019;50(10):4798-813. https://doi.org/10.1007/s11661-019-05375-x
  » https://doi.org/10.1007/s11661-019-05375-x
• ⁴⁸ Farag AA. Applications of nanomaterials in corrosion protection coatings and inhibitors. Corros Rev. 2020;38(1):67-86. https://doi.org/10.1515/corrrev-2019-0011
  » https://doi.org/10.1515/corrrev-2019-0011
• ⁴⁹ Ji P, Long R, Hou L, Wu R, Zhang J, Zhang M. Study on hydrophobicity and wettability transition of Ni-Cu-SiC coating on Mg-Li alloy. Surf Coat Tech. 2018;350:428-35. https://doi.org/10.1016/j.surfcoat.2018.07.038
  » https://doi.org/10.1016/j.surfcoat.2018.07.038
• ⁵⁰ Benea L, Bonora PL, Borello A, Martelli S. Wear corrosion properties of nano-structured SiC–nickel composite coatings obtained by electroplating. Wear. 2001;249(10-11):995-1003. https://doi.org/10.1016/S0043-1648(01)00844-4
  » https://doi.org/10.1016/S0043-1648(01)00844-4
• ⁵¹ Al-Asadi MM, Al-Tameemi HA. A review of tribological properties and deposition methods for selected hard protective coatings. Tribol Int. 2022;176:107919. https://doi.org/10.1016/j.triboint.2022.107919
  » https://doi.org/10.1016/j.triboint.2022.107919
• ⁵² Kazimierczak H, Szymkiewicz K, Gileadi E, Eliaz N. The effect of direct and pulsed current in the presence of surfactants on the electrodeposition of Zn–SiC nanocomposite coatings. Coatings. 2019;9(2):93. https://doi.org/10.3390/coatings9020093
  » https://doi.org/10.3390/coatings9020093
• ⁵³ Lanzutti A, Lekka M, De Leitenburg C, Fedrizzi L. Effect of pulse current on wear behavior of Ni matrix micro-and nano-SiC composite coatings at room and elevated temperature. Tribol Int. 2019;132:50-61. https://doi.org/10.1016/j.triboint.2018.12.011
  » https://doi.org/10.1016/j.triboint.2018.12.011

Edited by

• Associate Editor:
  Ana Sofia de Oliveira.

• Editor-in-Chief:
  Luiz Antonio Pessan.

Data availability

The entire dataset supporting the results of this study was published in the article itself.

Publication Dates

• Publication in this collection
  21 Nov 2025
• Date of issue
  2025

History

• Received
  25 Feb 2025
• Reviewed
  21 Aug 2025
• Accepted
  21 Sept 2025