Characterization and Sintering of AA1100 Powder Manufactured via High-Energy Ball Milling in an Isopropyl Alcohol Bath

Abstract

This study investigates the influence of milling parameters and nanosized alumina (Al₂O₃) reinforcement on the production of AA1100 via high-energy ball milling (HEBM) in a bath of isopropyl alcohol. X-ray Diffraction (XRD), Laser Diffraction (LD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and density measurements were employed to evaluate the effects of varying milling time, ball-to-powder ratio (BPR), and the addition of Al₂O₃. The powders were compacted and subjected to solid-state sintering, examined by SEM, and Vickers microhardness testing. The milling condition of 240 minutes with a BPR of 9:1 and no reinforcement promoted a balanced energy input and superior performance, yielding a crystallite size of 32 nm, particle size of 13,52 µm, and density of 2.179 g/cm³. The sintered specimen produced from this condition demonstrated the best densification, with an average Vickers microhardness value of 143 HV.

Keywords:
AA1100 Powder; High-Energy Ball Milling; Sintering

1. Introduction

Aluminum and its alloys have attracted growing interest in recent decades due to their excellent combination of mechanical, thermal, and physical properties, including low density, good corrosion resistance, high electrical and thermal conductivity, and significant formability. These characteristics make aluminum alloys ideal candidates for various industrial sectors, including aerospace, automotive, packaging, and electronics¹,². In this context, AA1100 is widely used in industry owing to its high ductility, good mechanical strength, excellent corrosion resistance, and superior thermal and electrical conductivity³-⁶.

The mechanical performance of aluminum alloys can be significantly enhanced through the incorporation of ceramic reinforcements, leading to the development of aluminum metal matrix composites (AMMCs). The final properties of AMMCs depend on several parameters, including the type and quantity of reinforcement, the matrix-reinforcement compatibility, and the particle size, morphology, and distribution⁷,⁸.

Among the various reinforcements, aluminum oxide (Al₂O₃) is particularly attractive due to its high hardness, thermal stability, and chemical compatibility with aluminum. The incorporation of Al₂O₃ particles into the aluminum matrix has been shown to improve hardness, reduce wear rate, and increase the composite's mechanical strength⁹-¹¹.

Furthermore, High-Energy Ball Milling (HEBM) has emerged as a promising technique for synthesizing aluminum alloys, as it allows for uniform dispersion of ceramic particles, grain refinement, and solid-state alloying. This process reduces crystallite and particle size while altering morphology until the equilibrium state. HEBM utilizes high-frequency impacts causing severe plastic deformation, cold welding of the particles, and repeated fracturing. This facilitates the formation of atomic-level bonds between the constituent elements in the solid state, creating a more homogeneous material with optimized properties¹²-²¹.

On the other hand, the choice of milling medium plays a crucial role in the HEBM process. Wet milling in a liquid medium, such as isopropyl alcohol, can improve particle dispersion and reduce agglomeration, resulting in finer powders compared to dry milling. However, it may also introduce process-related challenges, such as contamination and changes in particle surface energy²²-²⁴.

Finally, sintering is employed to consolidate the powders into dense bulk materials. This thermal treatment enhances interparticle bonding and promotes densification, thereby improving the mechanical integrity of the final product. The optimization of sintering parameters, such as temperature and duration, is essential for achieving desirable microstructural and mechanical properties²⁵,²⁶.

Theoretically, the optimum range of sintering temperatures would be between 60% and 80% of the matrix melting temperature, depending on the part thickness, and sintering time. Longer times and nanosize particles tend to sinter at lower temperatures, while a high sintering temperature tends to block up the fine pores, reducing the total number of pores²⁷.

Therefore, this study investigates the influence of milling parameters of time, ball-to-powder ratio (BPR), and the addition of nanosized Al₂O₃ on the microstructure and mechanical properties of AA1100 powders processed via HEBM in isopropyl alcohol and sintering, because it remains a relatively underexplored approach. The objective is to identify optimal processing conditions that enhance material performance, thereby contributing to the development of advanced aluminum-based materials for structural and functional applications.

2. Experimental Procedure

Table 1 presents the chemical composition of the AA1100 aluminum alloy expressed as a weight percentage used for research as a matrix. This AA1100 alloy, with 99.7% and a particle size of D₅₀ = 35 μm, was produced by Alcoa Aluminum Company. Besides, the Al₂O₃ nanometric powders, with a particle size D (50) 50 nm, supplied by Sigma-Aldrich Corporate, have been used as reinforcements.

Table 1
Chemical Composition AA1100 powder.

Material	Al (Min)	Si (Max)	Fe (Max)	Others (Max)
Weight %	99.7	0.25	0.15	0.15

For each specimen, a bath of isopropyl alcohol (C₃H₇OH) with a purity of 99.82% was combined with 1% by weight of zinc stearate (C₃₆H₇₀O₄Zn) to serve as wet grinding media. A SPEX-type vibratory mill set at 720 rpm ground the powder material in a milling container made of AISI 304L stainless steel, along with 100C6 steel spheres (composition: 1% carbon, 1.5% chromium) that had an average diameter of 6.4 mm.

The experimental conditions involved varying the milling times of 30, 60, 120, 240, and 480 minutes, along with different ball-to-powder ratios (BPR) of 7:1, 9:1, and 12:1. Additionally, the reinforcement level of nanosize Al₂O₃ was assessed at 5% by weight. This final percentage was chosen due to previous work developed using TiC, demonstrating that crystallite size diminished as reinforcement concentration around 2 wt %²⁸.

Following milling, the samples were dried at 230 °C to eliminate residual alcohol, according to specific behavior²⁹,³⁰. Then, the powders were compacted to cylinder samples (diameter: 12 mm; height: 7 mm), applying 700 MPa for 10 minutes, and subjected to the solid-state sintering process.

According to a previous study, the sintering process was carried out in a vacuum oven at a pressure of -700 mmHg, with a controlled heating rate of 20 °C/min until reaching 500 °C. The temperature was held constant at 500 °C for 5 hours, followed by a controlled slow cooling within the furnace³¹.

The analysis conducted on the powders included crystallite size, particle size, morphology, and density, while the sintered samples included morphology and hardness.

X-ray diffraction (XRD) investigated the crystallite size, covering a range of 5º to 120°, with a scanning rate of 0.02°/s, under a voltage of 40 kV and a current of 30 mA. The crystallite size was calculated from the Full Width at Half Maximum (FWHM) of the four principal aluminum peaks using the linear regression method of the Williamson–Hall plot equation (Equation 1)³²,³³. This approach achieved a confidence level of 95%. The Match Phase Analyses software identified the phases and indexed the diffraction peaks. Besides, the comparative evaluation excluded the impact of instrumental broadening on crystallite size and the microdeformation present in the material.

$$\text{FWHM}=\frac{k\lambda }{L\cos \theta }+4\epsilon \tan \theta$$ (1)

FWHM represents the full width at half maximum in radians; "k" is a dimensionless constant with a value of 0.94; "λ" is the x-ray wavelength, specified as 15.4 nm; "L" indicates the average crystallite size; "θ" is the Bragg angle, and "ε" denotes the microstrain present in the material.

The particle size was measured by Laser Diffraction (LD) using Malvern Mastersizer 2000. The samples were suspended in water or alcohol and subjected to ultrasonic agitation, covering a size range from 0.02 μm to 2000 μm.

When a laser beam interacts with a collection of particles dispersed in a liquid or air stream, it causes light scattering on the particles which are considered spherical in volume. The angles of scattering or diffraction exhibit distinct characteristics based on the particle size, with these angles gradually decreasing as the particle size increases³⁴.

The calculation of the average particle size and uncertainty assumes a distribution histogram. Measure D(0.5) represents the median particle diameter and corresponds to the 50th percentile of the cumulative undersize distribution³⁵,³⁶.

Additionally, a precision balance and a water container were employed to measure the density of the specimens using Archimedes’ principle, following the ASTM B962-13 standard³⁷. The reported density values represent the average of three measurements taken for each specimen.

The morphology was analyzed using a TESCAN MIRA 3 - Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS).

Vickers Hardness (HV) analysis was realized by the standard UNE-EN ISO 6507-1:2023³⁸ using a microdurometer (Shimadzu) with a load of HV (0.05).

3. Results and Discussion

All the powder results are presented to compare the AA1100 as-received, AA1100 processed as a function of milling time, AA1100 as a function of ball-to-powder ratio (BPR), and AA1100 as a function of Al₂O₃ reinforcement percentage. On the other hand, the sintered specimen results showed the morphology and values obtained by the Vickers microhardness testing.

3.1. Powder analysis

3.1.1. AA1100 as a function of milling time

The study was conducted with a ball-to-powder ratio (BPR) of 9:1. Table 2 provides a quantitative summary of the results for the AA 1100 powder in its as-received state and after processing AA1100 as a function of milling time. Figures 1-4 show the diffractograms, the particle size distribution curves, density, and powder morphology, respectively.

Table 2
Values of crystallite size, particle size, and density powder for samples AA1100 as received, milling in isopropyl alcohol as a function of milling time (720 RPM - BPR 9:1).

Sample [nº]	Milling Time [min]	Crystallite Size [nm]	Particle Size D (0.5) [µm]	Density [g/cm3]
1	as received	49	34.09	2.467
2	30	37	47.75	2.257
3	60	37	38.42	2.248
4	120	35	18.87	2.239
5	240	32	13.52	2.179
6	480	31	10.62	2.144

Figure 1
AA1100 powder x-ray diffraction as received and milling in isopropyl alcohol as a function of milling time.

Figure 4
SEM AA1100 (1000x): as received (A), milling in isopropyl alcohol at 60 min (B), 240 min (C), and 480 min (D).

The as-received powder shows a rounded morphology due to the atomization process by gas³⁹, with a particle size (D50) of 34.09 μm and an initial crystallite size, as measured by XRD, of 49 nm.

Figure 1 illustrates that the X-ray diffraction (XRD) peaks become broader and less intense with increasing milling time, indicating a reduction in crystallite size of 31 nm, as shown in Table 2, due to increased microstrain and material refinement⁴⁰.

Additionally, the evolution of the particle size distribution is presented in Figure 2, where the D (50) values decrease from approximately 10 μm. This behavior is attributed to the cold-welding and repeated fracturing phenomenon induced by the HEBM process⁴¹.

Figure 2
AA1100 powder laser diffraction spectrum as received and milling in isopropyl alcohol as a function of milling time.

Figure 3 and Table 2 present a decrease from 2.467 g/cm³ to 2.144 g/cm³ in bulk density as milling time increases. This trend is attributed to the increased specific surface area and reduced average particle size. As the original structure of the material is progressively broken down, smaller and more numerous particles are formed. This microstructural refinement increases the total surface area and contributes to a reduction in bulk density due to the larger occupied volume of the fine particles when applying the same compaction pressure⁴²,⁴³.

Figure 3
AA1100 powder density as received and milling in isopropyl alcohol as a function of milling time.

Furthermore, the morphological evolution of powders is presented in Figure 4. After 60 minutes of milling time, the particles become flattened due to the competing effects of cold welding and fracturing. After 240 minutes, a quasi-equilibrium state is achieved, dominated by fracturing mechanisms, consistent with previous studies⁴⁴,⁴⁵.

The results observed in crystallite size and particle size distribution are compatible with the changes in density and particle morphology. The sample milled for 480 minutes exhibited the most refined and uniformly distributed particles, indicating the most effective processing condition. However, the specimen milled for 240 minutes - presenting a crystallite size of 32 nm, a D (50) particle size of 13.5 μm, and a density of 2.179 g/cm³ - achieved values comparable to those obtained at 480 minutes (31 nm, 10.56 μm, and 2.144 g/cm³, respectively), with only marginal improvements observed beyond this point. Therefore, the additional energy input associated with prolonged milling may not be justified in terms of property enhancement.

Finally, Table 3 and Figures 5-8 present the EDS microanalysis results, demonstrating that the milling process did not qualitatively alter the elemental composition of the material. No contamination from the steel balls or the SPEX vibratory mill was detected.

Table 3
Micro analyses of EDS AA 1100: as received, milling in isopropyl alcohol as a function of milling time (720 RPM - BPR 9:1).

Element	As Received		Milled 60 min		Milled 240 min		Milled 480 min
	Weight (%)	Error	Weight(%)	Error	Weight (%)	Error	Weight(%)	Error
Aluminum	89.45	±0.1	95.14	±0.10	89.26	±0.34	91.31	±0.12
Oxygen	10.55	±0.1	4.84	±0.08	10.64	±0.11	8.66	±0.11
Manganese	-	-	0.01	±0.01	0.05	±0.01	-	-
Zinc	-	-	0.01	±0.01	0.03	±0.01	-	-
Cooper	-	-	-	-	0.01	±0.01	0.03	±0.01

Figure 5
EDS of the AA1100 powder as received.

Figure 6
EDS of the AA1100 powder – milling in isopropyl alcohol at 60 min.

Figure 7
EDS of the AA1100 powder – milling in isopropyl alcohol at 240 min.

Figure 8
EDS of the AA1100 powder – milling in isopropyl alcohol at 480 min.

3.1.2. AA1100 as functions of ball-to-powder ratio (BPR)

Tables 4 and 5 and Figures 9-16 summarize the results related to the variation in the BPR at 240 minutes for the specimens analyzed.

Table 4
Values of crystallite size, particle size, and density powder for samples AA1100 as received, milling in isopropyl alcohol as a function of BPR (720 RPM – 240 min).

Sample [nº]	BPR	Crystallite Size [nm]	Particle Size D (0.5) [µm]	Density [g/cm3]
1	As received	49	34.09	2.467
2	7:1	37	20.59	2.186
3	9:1	32	13.52	2.179
4	12:1	11	13.78	1.708

Table 5
Microanalyses of EDS AA 1100: as received, milling in isopropyl alcohol as a function of BPR (720 RPM – 240 min).

Element	As Received		Milled BPR 7:1		Milled BPR 9:1		Milled 12:1
	Weight (%)	Error	Weight(%)	Error	Weight (%)	Error	Weight(%)	Error
Aluminum	89.45	±0.1	88.87	±0.18	89.26	±0.34	45.43	±0.11
Oxygen	10.55	±0.1	10.97	±0.14	10.64	±0.11	54.49	±0.11
Manganese	-	-	0.09	±0.01	0.05	±0.01	0.03	±0.01
Zinc	-	-	0.01	±0.01	0.03	±0.01	-	-
Cooper	-	-	0.06	±0.01	0.01	0.01	0.04	±0.01

Figure 9
AA1100 powder x-ray diffraction as received and milling in isopropyl alcohol as a function of BPR.

Figure 16
AA1100 x-ray diffraction as received, milling in isopropyl alcohol as a function of Al₂O₃ reinforcement.

According to Table 4 and Figures 9-12, the BPR of 12:1 yielded significant results overall, producing a crystallite size of 11 nm and a density of 1.708 g/cm³. However, the particle size distribution for this condition, with a D (50) value of 13.78 μm, was slightly less favorable when compared to the BPR of 9:1, which exhibited a D (50) value of 13.52 μm and a more uniform distribution (Figure 10). Figure 9 displays a marked reduction in diffraction peak intensity and broader peaks for the BPR 12:1 specimen, indicating pronounced refinement. These findings are consistent with the density values observed in Figure 11 and particle morphology shown in Figure 12.

Figure 12
SEM AA1100 (1000x): as received (A), milling in isopropyl alcohol at BPR 7:1 (B), 9:1 (C), and 12:1 (D).

Figure 10
AA1100 powder laser diffraction spectrum as received and milling in isopropyl alcohol as a function of BPR.

Figure 11
AA1100 density powder as received, milling in isopropyl alcohol as a function of BPR.

The relationship between increasing the BPR and the energy applied during the milling was evident. The increase in the BPR resulted in greater energy transfer to the system, which in turn promoted enhanced particle refinement⁴⁶. However, an excessively high BPR can negatively affect efficiency, increasing equipment wear and promoting particle agglomeration. This balance is crucial for optimizing productivity and preventing damage to the mill. The ideal BPR is the one that provides the best conditions for achieving the equilibrium milling state, ensuring higher productivity⁴⁷.

The BPR of 12:1 generated excessive heat, causing the isopropyl alcohol to evaporate and increasing the internal pressure of the equipment. This situation raises safety concerns during processing. In contrast, a BPR of 9:1 demonstrated better stability, making it the more practical and controlled option.

Moreover, Table 5 and Figures 13-15 indicate that the increased oxygen content observed in the BPR 12:1 specimen may be attributed to the evaporation of the alcohol, which left residual traces within the material. These residues may have interacted with the particle surfaces, resulting in an apparent increase in oxygen detected during the EDS analysis. This effect is more pronounced in the 12:1 condition due to the highly fragmented and reactive nature of the particles produced under this milling regime.

Figure 13
EDS of the AA1100 powder – BPR 7:1.

Figure 14
EDS of the AA1100 powder – BPR 9:1.

Figure 15
EDS of the AA1100 powder – BPR 12:1.

3.1.3. AA1100 as functions of Al₂O₃ reinforcement

A comparative analysis of the samples highlights the significant influence of Al₂O₃ addition on the material’s properties analyzed at 240 minutes and BPR 9:1. Tables 6 and 7 and Figures 16-20 summarize the results related to the incorporation of the reinforcement in the samples.

Table 6
Values of crystallite size, particle size, and density powder for samples AA1100 as received, milling in isopropyl alcohol as a function of Al₂O₃ reinforcement (720 RPM – 240 min – BPR 9:1).

Sample [nº]	Reinforce Al2O3 [%]	Crystallite Size [nm]	Particle Size D (0.5) [µm]	Density [g/cm3]
1	As received	49	34.09	2.467
2	0	32	13.52	2.179
3	5	28	18.90	2.091

Table 7
Microanalyses of EDS AA1100: as received, milling in isopropyl alcohol as a function of Al₂O₃ reinforcement (720 RPM – 240 min – BPR 9:1).

Element	As Received		Milled no Reinforce		Milled 5% Reinforce
	Weight (%)	Error (%)	Weight(%)	Error	Weight (%)	Error
Aluminum	89.45	±0.1	89.26	±0.18	50.09	±0.13
Oxygen	10.55	±0.1	10.64	±0.14	49.76	±0.13
Manganese	-	-	0.05	±0.01	0.05	±0.01
Zinc	-	-	0.03	±0.01	0.06	±0.01
Cooper	-	-	0.01	±0.01	0.08	0.01

Figure 20
EDS of the AA1100 powder - 5% Al2O3.

Table 6 and Figures 16-19 demonstrate a response like that observed in the BPR analysis, attributed to the enhanced material refinement achieved through the addition of Al₂O₃. The presence of Al₂O₃ in the matrix promoted a progressive reduction in crystallite size (28 nm) and density (2.09 g/cm³), comparable to the refinement effect associated with increased energy transfer resulting from higher BPR values.

Figure 19
SEM AA1100 (1000x) as received (A), milling in isopropyl alcohol no reinforce (B), and 5% reinforce (C).

As shown in Figure 16, the diffractograms of the Al₂O₃-reinforced specimen exhibit a significant reduction in diffraction peak intensity while maintaining the same peak positions observed in the original powders, apart from the characteristic peaks of Al₂O₃ phases.

However, the average particle size distribution increased in the Al₂O₃-reinforced samples (18.90 μm) compared to the unreinforced sample (13.52 μm), as shown in Figure 17, suggesting a tendency toward particle agglomeration. Furthermore, the density measures agree with the material refinement and morphology found (Figures 18 and 19).

Figure 17
AA1100 laser diffraction spectrum as received, milling in isopropyl alcohol as a function of Al2O3 reinforcement.

Figure 18
AA1100 density powder as received, milling in isopropyl alcohol as a function of Al2O3 reinforcement.

These results emphasize the importance of controlling the concentration of nanometric reinforcements. Despite concentrations between 0% and 5% improving structural refinement and distribution control. Beyond this threshold, the positive effects of the reinforcement begin to diminish, leading to increased particle size and potential difficulties in achieving a homogeneous dispersion of material⁴⁸. In this case, the 5% value promoted some particle agglomeration.

Finally, the EDS analysis revealed a significant oxygen percentage in the reinforced sample. This phenomenon may be attributed to the residual evaporation of isopropyl alcohol on the material's surface.

3.2. Sintered specimen analysis

3.2.1. Morphology

Figure 21 presents the microstructural morphology of the sintered specimens, highlighting the main powder conditions and their respective influences on grain distribution and microstructure.

Figure 21
SEM AA1100 of sintered specimens (2000x): as received (A), milling in isopropyl alcohol 240 min-BPR 7:1 (B), 240 min-BPR 9:1(C), 240 min-BPR 9:1 and 5% Al2O3 reinforcement (D); 240 min-BPR 12:1 (E); 480 min - BPR 9:1 (F).

The specimen subjected to milling conditions of 240 minutes, BPR 9:1, and no reinforcement exhibited the lowest porosity and excellent structural consolidation during the sintering process. This milling condition was the most favorable due to the balance of energy found. In contrast, the specimen subjected to 240 minutes, BPR 7:1, and no reinforcement displayed higher porosity, suggesting the low BPR hindered the consolidation process. The crystallite and particle size variation increased the porosity due to minor material thermal stability promoted by the Hall-Petch effect⁴⁹.

Additionally, the specimens processed with a BPR of 12:1 and reinforced with nanosized Al₂O₃ exhibited increased oxygen content, as evidenced by EDS analysis. This condition hindered the consolidation process due to particle agglomeration and irregular morphology, resulting in higher porosity compared to unreinforced samples⁵⁰.

3.2.2. Vickers hardness

Figure 22 presents the Vickers hardness values for the specimens under the principal powder conditions of the study. The sample received present value 43 HV like reference to comparation.

Figure 22
Vickers hardness of the specimens: as received, milling in isopropyl alcohol 240 min-BPR 7:1, 240 min-BPR 9:1, 240 min-BPR 9:1 and 5% Al2O3 reinforcement; 240 min-BPR 12:1; 480 min - BPR 9:1.

Specimen processed for 240 minutes with a BPR of 9:1 and no reinforcement exhibited the highest hardness (143 HV) according to the morphology at sintering. On the other hand, at 480 minutes with a BPR 9:1 and no reinforcement, the hardness remained unchanged compared to 240 minutes (143 HV). The larger error bar observed at this point is associated with variations in the material's homogeneity caused by inconsistencies in particle distribution arising from prolonged milling, affecting the uniformity of the material.

The samples with BPR 12:1 and 5% Al₂O₃ showed a decrease in hardness compared to the unreinforced sample, respectively, 85 HV and 86 HV, due to the reduced material consolidation.

4. Conclusion

In this study, AA1100 powder was processed via High-Energy Ball Milling (HEBM) in an isopropyl alcohol bath to investigate the influence of milling time, ball-to-powder ratio (BPR), and the addition of Al₂O₃ reinforcement. The following conclusions were drawn:

The condition of 240 minutes of milling at a BPR of 9:1 without reinforcement provided a balanced energy input, resulting in crystallite size of 32 nm, particle size of 13.52 µm, and a density of 2.179 g/cm³. The sintered specimen from this condition exhibited the best densification and an average Vickers microhardness of 143 HV. Although the powder milled for 480 minutes under the same BPR showed slightly improved characteristics, it did not result in some increase in hardness, indicating that prolonged milling may not justify the additional energy consumption.

Conversely, increasing the BPR to 12:1 or incorporating 5 wt.% of Al₂O₃ reinforcement introduced excessive energy during the milling process. These conditions elevated oxygen content, promoted particle agglomeration, and induced morphological irregularities. Consequently, they negatively impacted on the material consolidation, reducing the Vickers microhardness to approximately 85 HV.

5. Acknowledgments

This work is part of projects: “Aluminum Metal Matrix Composite Ceramic Particulate Reinforcement,” supported by the National Council for Scientific and Technological Development (CNPq) – Brazil, at the Federal Rural University of Pernambuco, and “Functional,” a partnership between the Federal University of Pernambuco and the European Union’s Seventh Framework Programme for research, technological development, and demonstration under the People Programme: Marie Curie’s International Research Staff Exchange Scheme (Grant Agreement No 295254).

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

6. References

• ¹ Benjamin JS, Gilman PS. Mechanical Alloying. Annual Reviews Inc. 1983;13:279-300. http://doi.org/10.1146/annurev.ms.13.080183.001431.
• ² Chiaverini V. Powder metallurgy: techniques and products. 4th ed. São Paulo: ABM; 2001.
• ³ Surappa MK. Aluminium matrix composites: challenges and opportunities. Indian Institute Technology Ropar. 2003;28(1):319-34.
• ⁴ Callister WDJ. Materials science and engineering: an introduction. 7th ed. Rio de Janeiro: LTC; 2008.
• ⁵ Clyne TW, Withers PJ. An Introduction to metal matrix composites. Cambridge: Cambridge University Press; 1993.. http://doi.org/10.1017/CBO9780511623080
  » http://doi.org/10.1017/CBO9780511623080
• ⁶ Fogagnolo JB, Robert MH, Velasco F, Torralba JM. Aluminum matrix composites reinforced with Si₃N₄, AlN, and ZrB₂ produced by powder metallurgy and mechanical alloying. Kona Powder Particle J. 2004;22:143-50. http://doi.org/10.14356/kona.2004017
  » http://doi.org/10.14356/kona.2004017
• ⁷ Chen C, Wang W, Guo Z, Sun C, Volinsky AA, Paley V. Annealing effects on microstructure and mechanical properties of ultrafine-grained Al composite reinforced with nano-Al2O3 by rotary swaging. J Mater Eng Perform. 2018;27(4):1738-45. http://doi.org/10.1007/s11665-018-3301-2
  » http://doi.org/10.1007/s11665-018-3301-2
• ⁸ Rahimian M, Ehsani N, Parvin N, Baharvandi HR. The effect of particle size, sintering temperature, and sintering time on the properties of Al-Al2O3 composites, made by powder metallurgy. J Mater Process Technol. 2009;209(14):5387-93. http://doi.org/10.1016/j.jmatprotec.2009.04.007
  » http://doi.org/10.1016/j.jmatprotec.2009.04.007
• ⁹ Bülbül B, Okumus M. Microstructure, hardness, thermal and wear behaviours in Al–10Ni/TiO2 composites fabricated by mechanical alloying. Mater Chem Phys. 2022;281:125908. http://doi.org/10.1016/j.matchemphys.2022.125908
  » http://doi.org/10.1016/j.matchemphys.2022.125908
• ¹⁰ Demir ME, Çelik YH, Kalkanli A. The effect of rolling and aging on mechanical and tribological properties in B4C particle reinforced Al7075 matrix composites. Arab J Sci Eng. 2022;47(12):16187-208. http://doi.org/10.1007/s13369-022-06891-6
  » http://doi.org/10.1007/s13369-022-06891-6
• ¹¹ Demir ME, Okumuş M. Investigation of microhardness, microstructural, tribological, and thermal properties of Al7075/TiO₂/Kaoline hybrid metal matrix composites produced by powder metallurgy process. Adv Eng Mater. 2024;26(24):2401343. http://doi.org/10.1002/adem.202401343
  » http://doi.org/10.1002/adem.202401343
• ¹² Suryanarayana C. Powder metal technologies and applications. Almere: ASM International; 1998. (ASM Handbook; vol. 7).
• ¹³ Mhadhbi M. Modeling of the high-energy ball milling process. Adv Mater Phys Chem. 2021;11(1):31-44. http://doi.org/10.4236/ampc.2021.111004
  » http://doi.org/10.4236/ampc.2021.111004
• ¹⁴ Prabhakar DAP, Shettigar AK, Herbert MA, Patel G C M, Pimenov DY, Giasin K, et al. A comprehensive review of friction stir techniques in structural materials and alloys: challenges and trends. J Mater Res Technol. 2022;20:3025-60. http://doi.org/10.1016/j.jmrt.2022.08.034
  » http://doi.org/10.1016/j.jmrt.2022.08.034
• ¹⁵ Mhadhbi M. Effect of milling parameters on dem modeling of a planetary ball mill. Adv Mater Phys Chem. 2023;13(3):49-58. http://doi.org/10.4236/ampc.2023.134004
  » http://doi.org/10.4236/ampc.2023.134004
• ¹⁶ Moura ADA. Obtenção e caracterização de compósitos de matriz metálica da liga de alumínio AA1100 com reforço cerâmico particulado de carboneto de silício e alumina produzidos através de técnicas de metalurgia do pó [dissertation]. Recife: Universidade Federal de Pernambuco; 2013.
• ¹⁷ Moro N, Auras AP. Processos de fabricação: metalurgia do pó e o futuro da indústria. Florianópolis: CEFET; 2007.
• ¹⁸ Khan AS, Farrokh B, Takacs L. Effect of grain refinement on mechanical properties of ball-milled bulk aluminum. Mater Sci Eng A. 2008;489(1-2):77-84. http://doi.org/10.1016/j.msea.2008.01.045
  » http://doi.org/10.1016/j.msea.2008.01.045
• ¹⁹ Razavi-Tousi SS, Rad RY, Salahi E, Mobasherpour I, Razavi M. Production of Al-20 wt.% Al2O3 composite powder using high energy milling. Powder Technol. 2009;192(3):346-51. http://doi.org/10.1016/j.powtec.2009.01.016
  » http://doi.org/10.1016/j.powtec.2009.01.016
• ²⁰ Liao J, Tan MJ. Mixing of carbon nanotubes (CNTs) and aluminum powder for powder metallurgy use. Powder Technol. 2011;208(1):42-8. http://doi.org/10.1016/j.powtec.2010.12.001
  » http://doi.org/10.1016/j.powtec.2010.12.001
• ²¹ Sousa MMS. Estudo do processo de fabricação de compósitos de matriz metalúrgica de liga de alumínio AA6061 por metalurgia do pó via moagem de alta energia [dissertation]. Recife: Universidade Federal de Pernambuco; 2012.
• ²² Shtansky DV, Matveev AT, Permyakova ES, Leybo DV, Konopatsky AS, Sorokin PB. Recent progress in fabrication and application of BN nanostructures and BN-based nanohybrid. Nanomaterial. 2022;12(16):2810. http://doi.org/10.3390/nano12162810
  » http://doi.org/10.3390/nano12162810
• ²³ Kozawa T, Fukuyama K, Kushimoto K, Ishihara S, Kano J, Kondo A, et al. Effect of ball collision direction on a wet mechanochemical reaction. Sci Rep. 2021;11(1):210. http://doi.org/10.1038/s41598-020-80342-w
  » http://doi.org/10.1038/s41598-020-80342-w
• ²⁴ Xavier EÍV, Fernandes LE, Nascimento DM, Silva ME Jr, Araujo OO Fo. Desenvolvimento de compósitos da liga de alumínio AA7075 reforçados com alumina e nitreto de silício através de técnicas de metalurgia do pó. In: 74º Congresso Anual da ABM; 2019; São Paulo. Proceedings. São Paulo: ABM; 2019. http://doi.org/10.5151/2594-5327-33231
  » http://doi.org/10.5151/2594-5327-33231
• ²⁵ Favretto GB. Caracterização mecânica do compósito Al - Fe2Al5 sinterizado [dissertation]. Pato Branco: Universidade Tecnológica Federal do Paraná; 2017.
• ²⁶ Barbosa W, Pina EAC, Moura ADA, Rodrigues PR, Araujo OO Fo, Melo IR, et al. Nanostructured powders of AA7075 – SIC manufactured by high-energy ball milling in a bath of isopropyl alcohol. Mater Res. 2023;26:e20230230. http://doi.org/10.1590/1980-5373-mr-2023-0230
  » http://doi.org/10.1590/1980-5373-mr-2023-0230
• ²⁷ Thomas S, Kalarikkal N, Abraham AR. Design, fabrication, and characterization of multifunctional nanomaterials. Amsterdam: Elsevier; 2021. https://doi.org/10.1016/C2019-0-00948-X.
• ²⁸ Cruz S, Rey P, Román M, Merino P. Influence of content and particle size on properties of TiC reinforced 7075 aluminum matrix composites. In: 15th European Conference on Composite Materials; 2012; Venice, Italy. Proceedings. Padova: University of Padova; 2012. p. 1-8.
• ²⁹ Lira HM, Barbosa WAO, Pina EAC, Moura ADA, Rodriguez PR, Melo IR, et al. Manufacturing of AA7075 aluminum alloy composites reinforced by nanosize particles of SIC, TIN and ZnO by high-energy ball milling and hot extrusion. Mater Res. 2023;26:e20230154. http://doi.org/10.1590/1980-5373-mr-2023-0154
  » http://doi.org/10.1590/1980-5373-mr-2023-0154
• ³⁰ Ayoub JP, Oliveira MRN. Manufacturing of aluminum alloy AA1100 composite reinforced with Al₂O₃ processed by high-energy milling. In: Ayoub J, Oliveira M, editors. Engineering materials: fundamentals and new trends. 1st ed. São Paulo: Científica Digital; 2024. p. 57-77. (vol. 3).
• ³¹ Contreras AR, Punset M, Calero JA, Gil FJ, Ruperez E, Manero JM. Power metallurgy with space holder for porous titanium implants: A review. J Mater Sci Technol. 2021;76:120-49. http://doi.org/10.1016/j.jmst.2020.11.005.
• ³² Monshi A, Foroughi MR, Monshi MR. Modified Scherrer equation to estimate more accurately nano-crystallite size using XRD. WJNSE. 2012;2(3):154-60. http://doi.org/10.4236/wjnse.2012.23020
  » http://doi.org/10.4236/wjnse.2012.23020
• ³³ ISO: International Organization for Standardization. ISO 13320: particle size analysis: laser diffraction methods. Genève: ISO; 2020.
• ³⁴ Syvitski JPM, editor. Principles, methods, and application of particle size analysis. Cambridge: Cambridge University Press; 1991. http://doi.org/10.1017/CBO9780511626142
  » http://doi.org/10.1017/CBO9780511626142
• ³⁵ Svensson DN, Messing I, Barron J. An investigation in laser diffraction soil particle size distribution analysis to obtain compatible results with sieve and pipette method. Soil Tillage Res. 2022;223:105450. http://doi.org/10.1016/j.still.2022.105450
  » http://doi.org/10.1016/j.still.2022.105450
• ³⁶ ISO: International Organization for Standardization. ISO 9276-1: representation of results of particle size analysis – Part 1: graphical representation. Genève: ISO; 1998.
• ³⁷ ASTM: American Society for Testing and Materials. ASTM 962-13: standard test methods for density of compacted or sintered powder metallurgy (PM) products using Archimedes’ principle. West Conshohocken: ASTM; 2013.
• ³⁸ ISO: International Organization for Standardization. ISO 6507-1: metallic materials: vickers hardness test – Part 1: test method. Genève: ISO; 2018.
• ³⁹ Grupo Setorial de Metalugia do Pó. Powder metallurgy: an economical alternative with lower environmental impact. 2nd ed. São Paulo: Metallum Eventos Técnicos; 2009.
• ⁴⁰ Fernández H, Ordoñez S, Pesenti H, González RE, Leoni M. Microstructure homogeneity of milled aluminum A356–Si3N4 metal matrix composite powders. J Mater Res Technol. 2019;8(3):2969-77. http://doi.org/10.1016/j.jmrt.2019.05.004
  » http://doi.org/10.1016/j.jmrt.2019.05.004
• ⁴¹ Cao W. High energy ball milling process for nanomaterial synthesis [Internet]. Houston: Skyspring Nanomaterials; 2022 [cited 2023 Feb 28]. Available from: https://www.understandingnano.com/nanomaterial-synthesis-ball-milling.html
  » https://www.understandingnano.com/nanomaterial-synthesis-ball-milling.html
• ⁴² Torres CS, Shaeffer L. Effect of high energy milling on the morphology and compressibility of WC-Ni composite powder. Materia. 2010;15(1):88-95. http://doi.org/10.1590/S1517-70762010000100011.
• ⁴³ Singh P, Abhash A, Yadav BN, Shafeeq M, Singh IB, Mondal DP. Effect of milling time on powder characteristics and mechanical performance of Ti4wt%Al alloy. Powder Technol. 2019;342:275-87. http://doi.org/10.1016/j.powtec.2018.09.075
  » http://doi.org/10.1016/j.powtec.2018.09.075
• ⁴⁴ Salah N, Habib SS, Khan ZH, Memic A, Azam A, Alarfaj E, et al. High energy ball milling technique for ZnO nanoparticles antibacterial material. Int J Nanomedicine. 2011;6:863-9. http://doi.org/10.2147/IJN.S18267
  » http://doi.org/10.2147/IJN.S18267
• ⁴⁵ Soares E, Bouchonneau N, Alves E, Alves K, Araújo Filho O, Mesguich D, et al. Microstructure and mechanical properties of AA7075 aluminum alloy fabricated by spark plasma sintering (SPS). Materials. 2021;14(2):430. http://doi.org/10.3390/ma14020430
  » http://doi.org/10.3390/ma14020430
• ⁴⁶ Rios J, Restrepo A, Zuleta A, Bolivar F, Castaño R, Correa E, et al. Effect of ball size on the microstructure and morphology of Mg powders processed by high-energy ball milling. Metals. 2021;11(10):1621. http://doi.org/10.3390/met11101621
  » http://doi.org/10.3390/met11101621
• ⁴⁷ Estrada-Ruiz RH, Flores-Campos R, Treviño-Rodríguez GA, Herrera-Ramírez JM, Martínez-Sánchez R. Wear resistance analysis of the aluminum 7075 alloy and the nanostructured aluminum 7075 - silver nanoparticles composites. J Min Metall Sect B Metall. 2016;52:163-70. http://doi.org/10.2298/JMMB150103011E
  » http://doi.org/10.2298/JMMB150103011E
• ⁴⁸ Goujon C, Goeuriot P, Chedru M, Vicens J, Chermant JL, Bernard F, et al. Cryomilling of Al/AlN powders. Powder Technol. 1999;105(1-3):328-36. http://doi.org/10.1016/S0032-5910(99)00155-2
  » http://doi.org/10.1016/S0032-5910(99)00155-2
• ⁴⁹ Mohamed FA, Xun Y. Correlations between the minimum grain size produced by milling and material parameters. Mater Sci Eng. 2003;345A(1-2):133-9. http://doi.org/10.1016/S0921-5093(02)00936-X
  » http://doi.org/10.1016/S0921-5093(02)00936-X
• ⁵⁰ Isobe T, Ooyama A, Shimizu M, Nakajima A. Pore size control of Al2O3 ceramics using two-step sintering. Ceram Int. 2012;38(1):787-93. http://doi.org/10.1016/j.ceramint.2011.08.005
  » http://doi.org/10.1016/j.ceramint.2011.08.005

Edited by

• Associate Editor:
  Aloisio Klein.

• 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
  17 Oct 2025
• Date of issue
  2025

History

• Received
  24 Mar 2025
• Reviewed
  29 July 2025
• Accepted
  06 Sept 2025