Microstructure and mechanical properties of TiO2 reinforced ZA22 metal matrix composite

The mechanical and physical properties that are achieved with Zn-Al metal matrix composites (MMCs) have made them popular candidate materials for automotive, aerospace and several other applications. In recent years, Zn-Al alloys are used as bearing and bushing materials as a substitute for copper based and aluminium based bearing materials due to their relatively low costs and superior tribological characteristics. Additions of hard ceramic particulates like SiC, Al2O3, TiO2, graphite etc., contribute in significant improvement of mechanical properties and sliding wear behavior of MMCs. In the present work, four Zn-22Al-2.5Cu alloys were developed by addition of TiO2 varying between 0 and 6% through stir casting route. The effect of TiO2 addition on Zn-22Al-2.5Cu alloys has been investigated through microstructural study, tensile test, hardness test and wear characteristics. The alloy with 6% TiO2 addition revealed a dendritic structure and exhibited superior mechanical properties and sliding wear behavior over the other three compositions. (C) 2019 Elsevier Ltd. All rights reserved.