Investigation of Microstructure and Mechanical Properties of Ni-Cu-P Coatings Deposited by the Electroless Method

In the current study, the effect of colloidal copper nanoparticles on the deposition rate and hardness of Ni-Cu-P coating deposited by electroless method on L۸۰ steel substrate was investigated. Copper particle size, microstructure, chemical composition, and hardness of the coating before and after heat treatment at different temperatures were examined by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDS) analysis, and microhardness. The microstructure study by XRD showed that the Ni-Cu-P coating has an amorphous structure. The heat treatment at ۴۰۰ °C transformed the structure from amorphous to crystalline and formed Niα, Ni۳P, and Ni۳.۸Cu phases. The amount of copper nanoparticles in the coating ۴.۵۸ wt% was measured. The deposition rate of the Ni-Cu-P coating was ۱۱ µm/h. Furthermore, the hardness of the coating increased from ۷۳۸HV to ۱۳۰۰HV by performing heat treatment.

Keywords:

Electroless Ni-Cu-P , Microhardness , L۸۰ steel , TEM , Heat treatment