Study of fabrication and wear properties of Ni–SiC composite coatings on A356 aluminum alloy

Abstract

This study produces Ni–SiC composite coatings by electrodeposition with A356 aluminum alloy as the substrate. The concentration of SiC particles in the plating bath and the current density are varied to produce composite coatings with particle concentrations from 2.5 to 12.3 vol%, and hardness from 439 to 538 HV. Dry friction and lubrication friction experiments use a ball-on-disk to determine the frictional behavior of the Ni–SiC composite coatings. The coefficient of friction and wear resistance of a Ni–SiC composite coating is determined for different load and lubrication environments.The results show that in a dry friction environment, a composite coating with a SiC particle content of 8.0–10.0 vol% and a hardness of 500–540HV has a lower coefficient of friction and abrasion rate due to the high hardness and elastic modulus ratio (H/E). In a lubricating environment, load resistance is 150 N if the coating contains 8.0–10.0 vol% particles. When the load is increased to 200 N, a large number of SiC particles are removed due to friction so the Ni-12.3 vol%SiC many oil storage pores are created in the composite coating. This hydraulic lubrication produces a coating with better wear performance.