Evaluation of sliding wear behaviour of feldspar particle-reinforced magnesium alloy composites

The unlubricated sliding wear behavior of magnesium alloy AZ91 composites reinforced with feldspar particles of size 30-50 mu m was evaluated. The content of feldspar in the alloy was varied from 1% to 5% in steps of 2-wt.%. Liquid metallurgy technique was used to fabricate the composites. A pin-on-disc wear-testing machine was used to evaluate the wear rate, in which an EN24 steel disc was used as the counterface. Results indicated that the wear rates of the composites were lower than that of the matrix alloy and further decreased with the increase in feldspar content. However, in both unreinforced alloy and reinforced composites, the wear rates increased with the increase in load and the sliding speed. Increase in the applied load increased the wear severity by changing the wear mechanism from abrasion to particle cracking induced delamination wear. It was found that with the increase in feldspar content, the wear resistance increased monotonically. The observations have been explained using scanning electron microscopy (SEM) analysis of the worn surfaces and the subsurface of the composites. (C) 2000 Published by Elsevier Science S.A. All rights reserved.