Influence of load, sliding speed, and microstructure on wear response of AZ91 Mg alloy

Abstract

This article deals with the tribological study of solution-treated and peak aged AZ91 Mg alloy. Tribological studies were carried out using reciprocating sliding contact under lubricated conditions. The effect of load, sliding speed, and microstructure on wear response of AZ91 Mg alloy was investigated. The wear response was characterized using optical microscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy mapping. The peak aged alloy showed excellent wear resistance against Al6351 Al alloy as compared with solution-treated alloy. The formation of γ-Mg17Al12 precipitates in aged sample was found to increase the wear resistance. The specific wear rate for peak aged alloy was almost one-third than that of solution-treated alloy. In both the samples, i.e. solution-treated and peak aged, the coefficient of friction decreases with increase in sliding speed at low load, while the behavior of peak aged sample was found to be opposite at higher load. At low load, the wear mode for peak aged sample was oxidative which further shifted to adhesive at higher loads.