Sliding wear response of a zinc-based alloy and its composite and comparison with a gray cast iron: influence of external lubrication and microstructural features

The role played by an external lubricant and features of various material microconstituents towards controlling the wear behaviour of a zinc-based alloy reinforced with silicon carbide particles has been studied under varying load conditions, in this investigation. Testing the zinc-based matrix alloy under identical conditions enabled to assess the effect of the reinforcement particles on the wear characteristics of the alloy. The wear response of the samples was compared with that of a gray cast iron. In order to study the influence of the external lubricant, dry wear tests were also conducted on the materials. udy shows that the reinforcement of SiC particles substantially affected the wear response of the zinc-based alloy. The applied load and test duration influenced the wear characteristics of the samples in a mixed manner. The oil lubricant considerably improved the wear behaviour in terms of decreased wear rate, friction coefficient and frictional heating. The lubricant also narrowed down the difference in the wear performance of the zinc-based matrix alloy, composite and cast iron. In other words, the oil lubricant suppressed the effect of microstructural features of the samples on wear behaviour. l wear response under specific wear conditions has been discussed in terms of load bearing, lubricating and cracking characteristics of various microconstituents of samples and the effectiveness of oil lubricant to suppress the role played by the phases. The features of wear surfaces, subsurface regions and debris particles could further substantiate the observed wear response of the samples.