Effect of minor La addition on wear behaviour of Mg-10Dy alloy

Abstract

Magnesium alloys have attracted significant attention as a potential replacement material for aluminium alloys in the automobile industry due to their superior strength-to-weight ratio. The addition of rare earth elements to Mg alloys enhances its strength and tribological properties owing to the solid solution strengthening as well as increased melting temperatures of the second phase. The aim of the current study is to examine the effect of minor La addition on the wear behaviour of as-cast Mg-rare-earth alloy (Mg-10 wt%Dy) in dry sliding conditions at different loads. The addition of rare earth elements to the magnesium alloys improves the wear strength effectively at different loads. The experiments were performed using ball-on-disc tribometer with a steel ball counterface as a function of normal load and at a constant sliding velocity. The wear surfaces were analyzed using a 3D profilometer and a field emission scanning electron microscopy to investigate wear rate and wear mechanisms. It was observed that due to the formation of stable oxide surface layers and improved hardness of La containing alloy, the wear rate is significantly lower than the Mg-10Dy alloy at different applied normal loads. Abrasion, delamination, oxidation, and plastic deformation were established as the governing wear mechanisms.