Investigation of wear in aluminium matrix composite for automotive brake drum applications using statistical analysis

Abstract

The wear behaviour of Aluminium Metal Matrix Composite (Al MMC) and a commercial grey cast iron have been investigated using a pin on disc machine while sliding against an automotive brake shoe lining material. The wear tests have been carried out using pin as commercial brake shoe lining material and discs as A356/25SiCp Al MMC and grey cast iron materials. The Al MMC disc has been manufactured by stir casting technique using A356 aluminium alloy and 25% silicon carbide particles. From the brake drum of a passenger car, the grey cast iron disc has been machined. Pins of 10mm diameter have been machined from a commercial brake shoe lining of a passenger car. The wear behaviour of Al MMC and the grey cast iron have been investigated at different applied loads, sliding velocities and sliding distances. Mathematical models have been developed to predict the wear rate using a linear factorial design approach. The parameters x1, x2 and x3 have been used to represent the load, sliding velocity and sliding distance respectively. An excellent agreement has been observed between predicted and experimental results. For both materials the wear rate has been found to increase with applied load, sliding velocity and sliding distance. The worn surfaces of MMC, the cast iron and the lining have been analysed using optical micrographs. © Freund Publishing House Ltd.