Abrasive Wear Response of SiC<sub>p</sub> Reinforced ZA-43 Alloy Metal Matrix Composite

Abstract

Objectives: The objectives of the present study are to synthesize the high aluminium content zinc based alloy and their composites by incorporating 5 and 10 wt% of SiC particles and to assess their two body abrasive wear response. Methods/ Analysis: The matrix alloy and their composites have been synthesized by liquid metallurgy route. High stress abrasive wear examiantion have been conducted on using a pin-on-disc wear tester as per ASTM G132-96 standard. The influence of abrading distance and applied load on the wear behaviour of the test materials have been studied. For understanding the wear mechanism of composite wear rate, friction coefficient and frictional heating have been determined. Findings: The zinc based matrix alloy exhibits dendritic structure comprising of α dendrites surrounded by α + η eutectoid and metastable ∈ phase. in interdendritic regions. The α+η is solid solution of zinc and aluminium in aluminium and zinc respectively are soft and ductile while ∈ phase is quite harder and transmits wear resistance to a slight range. The dispersed SiC particles are considerable harder than the base alloy and enhance the abrasion resistance of the matrix alloy. Increasing abrasive wear rate with test duration could be attributed to greater extent of materiel loss because of the cutting tendency of the abrasive. Higher wear rate with larger load was owing to relatively less deterioration in the cutting efficiency of the abrasive particles spread over fixed track area. Highest frictional heating of the matrix alloy could be because of a greater extent of penetration of the abrasive particles on the samples while dispersion of hard SiC particles reduces the severity of penetration. Higher frictional heating with increasing load may be acribed to a greater extent of penetration by the abrasive particles on the sample surface. The presence of hard SiC particles in the composite reduced the depth of cut by the abrasive leading to increase coefficient of friction than the base alloy. Novelty/Improvements: The present study evaluate the abrasive wear behavior of a lighter zinc-based alloy and their composites in order to substitute as an efficient material system to conventionally used materials in tribiological applications.