Effect of increasingly metallized hybrid reinforcement on the wear mechanisms of magnesium nanocomposite

Abstract

Strength and ductility of pure magnesium have experienced simultaneous improvement due to the presence of nanosize hybrid (yttria and copper) reinforcement. Increasing the vol% (i.e., 0.3-1.0) of ductile metallic copper particles in reinforcement has further enhanced the strength of magnesium. Wear behaviour of these magnesium hybrid nanocomposites was investigated using pin-on-disc dry sliding tests against hardened tool steel using a constant sliding speed of 1 m s-1 under a range of loads from 5 to 30 N for a sliding distance of 1000 m. Scanning electron microscopy identified abrasion and delamination as primary wear mechanisms in the hybrid nanocomposite. Oxidation was active in nanocomposite with higher copper content, tested under higher load and positively affected the wear resistance. Limited thermal softening was observed when tested at a relatively higher load. High frictional heat dissipation capacity couples with higher hardness resisted adhesive wear which is common mechanism for magnesium composite.