Wear resistance property and microstructure of magnesium AZ91 composite

The wear resistance of magnesium AZ91 composite produced by powder metallurgy technique and reinforced with 0, 5, 10, 15 and 20 wt.% SiC were being investigated. Pin-on-disk dry sliding wear tests were carried out to study the wear performance and wear mechanisms. The magnesium matrix composites were used as pins while the counterface consist of mild steel disks. After the wear tests, worn surfaces of pins and the wear debris were investigated using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The wear resistance performance of magnesium AZ91 composites was found to improve with increasing volume fraction of SIG. Volumetric wear was found to increase with increasing sliding distance and the wear rate was greatly reduced after the wear-in phenomenon. During the initial 50m of sliding distance, abrasion nas predominant. Oxidative wear took place when the sliding distance was between 50 and 250m while adhesive wear became predominant when the sliding distance had exceeded 250m.