Anti-fretting Properties of Ni/Ni-coated nano-Al_2O_3 Composite Coating Prepared by Electro-brush Plating

Nickel coated nano Al 2O 3 containing Ni based composite coating (coded as Ni/Ni coated Al 2O 3) was prepared by electro brush plating. The fretting properties of the composite coating were investigated on an SRV friction and wear tester. As the results, the composite coating has higher micro hardness than the conventional electro plated Ni coating. This is especially so at relatively high temperature. Ni/Ni coated Al 2O 3 composite coating shows better resistance to fretting than high speed nickel coating. It registers a lower friction coefficient than high speed nickel coating in sliding against AISI 1045 steel as well. This is attributed to the strengthening effect of the composite coating and the reinforcing effect of nano Al 2O 3 at relatively high temperature. The XPS and EDS analytical results of the worn coating surfaces indicate that the composite coating is characterized by adhesion and transfer of worn out materials in sliding against AISI 1045 steel.