Investigation on corrosion and wear behaviors of nanoparticles reinforced Ni-based composite alloying layer

In order to investigate the role of amorphous SiO₂ particles in corrosion and wear resistance of Ni-based metal matrix composite alloying layer, the amorphous nano-SiO₂ particles reinforced Ni-based composite alloying layer has been prepared by double glow plasma alloying on AISI 316L stainless steel surface, where Ni/amorphous nano-SiO₂ was firstly predeposited by brush plating. The composition and microstructure of the nano-SiO₂ particles reinforced Ni-based composite alloying layer were analyzed by using SEM, TEM and XRD. The results indicated that the composite alloying layer consisted of γ-phase and amorphous nano-SiO₂ particles, and under alloying temperature (1000 °C) condition, the nano-SiO₂ particles were uniformly distributed in the alloying layer and still kept the amorphous structure. The corrosion resistance of composite alloying layer was investigated by an electrochemical method in 3.5%NaCl solution. Compared with single alloying layer, the amorphous nano-SiO₂ particles slightly decreased the corrosion resistance of the Ni-Cr-Mo-Cu alloying layer. X-ray photoelectron spectroscopy (XPS) revealed that the passive films formed on the composite alloying consisted of Cr₂O₃, MoO₃, SiO₂ and metallic Ni and Mo. The dry wear test results showed that the composite alloying layer had excellent friction-reduced property, and the wear weight loss of composite alloying layer was less than 60% of that of Ni-Cr-Mo-Cu alloying layer.