Studies on Tribological Characteristics of Centrifugally Cast SiCp-Reinforced Functionally Graded A319 Aluminium Matrix Composites

Abstract

The concept of functionally graded materials is effectively applied to design and fabricate engineering components with location-specific wear resistance suited to the particular application. The present study describes the wear behaviour of centrifugally cast A319 aluminium functionally graded metal matrix composites (FGMMC) formed from 20 wt% SiCp-reinforced composite. Liquid stir casting method is used for homogeneous metal matrix composite preparation followed by vertical centrifugal casting for FGMMC rings production. Microstructure analysis of specimen reveals a homogeneous distribution of SiCp reinforcements for the gravity and a gradient particle distribution, in the radial direction forming different zones, for the centrifugal castings. The dry sliding wear behaviour is studied on a DUCOM pin-on-disc tribometer with steel disc and by using FGMMC pins produced from different zones. Wear studies show gradient tribological properties, within a component, with a maximum wear resistance at the particle rich region, lesser in transition zone and the minimum wear resistance at the inner zones. SEM observation confirms abrasive wear predominance by revealing the microgrooves and ploughing on the worn-out surfaces.