Wear behaviour of SiCp-reinforced magnesium matrix composites

This paper investigates the wear behaviour of magnesium (Mg)-based metal-matrix composites (MMCs) reinforced with silicon carbide particulates (SiCp) during dry sliding. Experiments were conducted using a pin-on-disc configuration against a hardened tool-steel counterface under loads of 10 and 30 N, and within a sliding velocity range of 0.2-5.0 m/s. The composites exhibit slightly superior wear resistance under the lower load, but the effects of the SiC particulate reinforcements on wear resistance are not as conclusive under the higher load. Scanning electron microscopic (SEM) examinations of the worn composites identified the following wear mechanisms: abrasion, oxidation, delamination, adhesion, thermal softening and melting. The useful range of Mg/SiCp composites appears to be limited to loads and speeds below 30 N and 5.0 m/s, respectively. Under this sliding condition, melt wear becomes the dominant wear mechanism, causing gross deformation of the magnesium matrix at the contacting interface, thus rendering any component useless. (C) 2003 Elsevier Science B.V. All rights reserved.