Sliding wear behaviour of zircon particles reinforced ZA-27 alloy composite materials

The present paper is a report of an investigation made to study the unlubricated sliding wear behaviour of zinc-aluminium (ZA) alloy composites reinforced with zircon particles of size 30-50 mu m The content of zircon in the alloy was varied from 1-5% in steps of 2 wt.%. The 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 a hardened EN24 steel disc was used as the counterface. The results indicated that the wear rate of the composites was lesser than that of the matrix alloy and it further decreased with the increase in zircon content. However, the material loss in terms of wear rate and the wear volume increased with the increase in load and sliding distance, respectively, both in the case of composites and the alloy. 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 zircon content, the wear resistance increased monotonically. The observations have been explained using scanning electron micrography (SEM) analysis of the worn surfaces and the subsurface of the composites as well as the base alloy. (C) 1999 Published by Elsevier Science S.A. All rights reserved.