Influence of phase composition on fretting wear behavior of thermally sprayed aluminum bronze coatings

Abstract

Single -phase and duplex (þ 0 ) phase aluminum bronze (CuAl) coatings were deposited on 1Cr18Ni9Ti stainless steels by atmosphere plasma spray. The fretting wear behaviors of the two types of coatings were investigated in relation to their phase composition. The damage mechanisms of the coatings were identified by analysing their worn surfaces using scanning electron microscopy and three-dimensional non-contact surface profiler. A discussion about the identified fretting damage mechanisms was carried out. Results show that duplex CuAl coating has higher hardness than the single a-phase CuAl coating but the former has poorer resistance against fretting wear than the latter in mixed stick-slip regime and gross slip regime. The toughness reduction due to the dendritic distribution of the 0 phase in duplex CuAl coating could explain the low fretting wear resistance observed in the duplex coating. In stick regime, single a-phase CuAl coating has a lower friction coefficient but it has a higher wear rate than the duplex coating, which is attributed to the lower hardness and hence more severe plastic deformation.