Dry sliding friction and wear behavior of HVOF-prepared CoCrAlSiY coating under different loads

Abstract

The CoCrAlSiY coating was fabricated via high-velocity oxy-fuel (HVOF) spraying, and its microstructure, tribological properties and stress distribution at the friction interface were systematically investigated. The as-deposited CoCrAlSiY coating is primarily composed of a metallic matrix phase CoAl, with minor oxide phases including CoCr 2 O 4 , Co 3 O 4 and α-Al 2 O 3 distributed uniformly on the surface, forming a compact structure. The tribological tests under different applied loads demonstrate that the CoCrAlSiY coating exhibits optimal tribological performance at a load of 7 N. Under this condition, the coating achieves the lowest friction coefficient and wear rate, which are 0.31 and 3.67×10 -5 mm 3 /(N·m), respectively. Compared with the worn surfaces under other loads, the wear track at 7 N is relatively smooth with only slight shallow grooves. The finite element simulation of the friction process further analyzes the stress distribution within the CoCrAlSiY coating under different loads, which helps interpret the experimental observation that the coating achieves the best friction and wear performance at 7 N. This study provides guidance for improving the service life and operational reliability of the coating under high-load conditions, and supplies a potential surface protection route for related industrial applications.