EFFECT OF SIC PARTICLE REINFORCEMENT ON THE UNLUBRICATED SLIDING WEARBEHAVIOR OF ZA-27 ALLOY COMPOSITES

In the present study, the effect of silicon carbide (SiC) reinforcemen t on the unlubricated sliding wear behaviour of ZA-27 alloy composites was investigated using a pin-on-disc sliding wear testing machine. Th e composite specimens were prepared using the liquid metallurgy techni que and the percentage of SiC was varied from 1-5% in steps of 2% by w eight. The sliding wear tests were conducted at loads of 3, 4, 5 and 6 kg (29.4, 39.2, 49.1 and 58.9 N, respectively) and rotational speeds of 200, 250 and 300 rpm (i.e., tangential speeds of 1.25, 1.56, 1.87 m /s respectively). The unreinforced alloy was also tested under identic al conditions in order to enable comparison. The results of the tests revealed that the SIC reinforced composites exhibited a lower wear rat e compared to the unreinforced alloy specimens. Increase in the applie d 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 SiC content, the wear resistance increased monotonically with hardness. SEM micrographs indicated the effect of S iC particles in reducing the wear rate of the material. (C) 1997 Elsev ier Science S.A.