Study on the role of element Mo in improving thermal stability and corrosion resistance of amorphous Ni-P deposit

Abstract

Amorphous Ni-4.31 wt. % Mo-12.89 wt.% P deposit and amorphous Ni-12.35 wt.% P deposit were produced by electroless deposition. The different structures were obtained by low temperature heat treatment. Effect of element Mo on microstructure evolution, thermal stability and corrosion resistance was studied by XRD and its corresponding pair density function, DSC, electrochemical examination and XPS. Results showed that adding element Mo could improve the thermal stability and amorphous tissues stability of Ni-P deposit. Furthermore, the Ni-Mo-P deposit had better corrosion resistance than the Ni-P deposit because the oxides and compounds formed by adding element Mo could effectively resist the perforation corrosion of chloride ions. The annealed Ni-Mo-P deposits with amorphous structure could form stable passivation films in neutral sodium chloride solution due to the more uniform distribution of oxides and compounds of element Mo.