Chemical coatings of Ni-P have been observed in various applications, such as, tools, molds and matrices, mainly to prevent wear and corrosion. In this present work, Ni-P coatings with 8 and 10%P were deposited on steel ABNT 1020 and heat-treated at temperatures between 300ºC and 650ºC for 1h. The microstructures, nickel and phosphates have been examined using a scanning electronic microscope (SEM). Analyses of Differential Scanning Calorimetry (DSC) has been carried out to detect reactions and transformations of the phases. The results of assay scratch revealed a variation of the adhesion of these coatings in function of the heat treatment temperature, as well as of the hardness to the scratch that reached a maximum value to 400ºC.
Ni-P; adhesion; hardness to the scratch
