Wear response of a Zn-base alloy in the presence of SiC particle reinforcement: A comparative study with a copper-base alloy

An attempt has been made in this study to examine the effects produced by t he reinforcement of (10 wt%) SiC particles on the sliding wear behavior of a Zn-base alloy. The matrix alloy was also subjected to identical test cond itions to assess the influence of the SiC dispersoid phase. The wear charac teristics of the (Zn-base alloy) composite and the matrix alloy were also c ompared with those of a Cu-base alloy (i.e., an aluminum bronze) in order t o understand the scope of exploiting the Zn-base alloy matrix/composite as a substitute material for the latter (Cu-base) alloy. It has been observed that low frictional heat generated at the lower slidin g speed (0.42 m/s) enabled the Zn-base (matrix) alloy to perform better tha n the composite material, while the Cu-base alloy showed intermediate wear resistance. On the contrary, the trend changed at a higher sliding speed (4 .62 m/s) when high frictional heating caused the wear behavior of the Cu-ba se alloy to be superior to that of the Zn-base (matrix) alloy. The composit e in this case performed better than the matrix alloy. The wear behavior of the specimens has been explained in terms of factors l ike microcracking tendency and thermal stability introduced by the SIC disp ersoid phase and lubricating, load bearing, and low melting characteristics of microconstituents like alpha and eta in the (Zn-base) alloy system and the thermal stability of the Cu-base alloy. It seems that the predominance of one set of parameters over the other actually controls the overall perfo rmance of a material. Once again, it is the test conditions that ultimately allow a particular set of factors to govern the other and influence the re sponse of the specimens accordingly. The observed wear behavior of the samp les has been substantiated further with their wear surface characteristics.