WEAR PERFORMANCE OF ALUMINUM-ALLOY COMPOSITES CONTAINING UNIDIRECTIONALLY-ORIENTED SILICON-CARBIDE COATED BORON FIBERS

The friction and wear behaviour of continuous, silicon carbide coated, unidirectional boron fibre reinforced aluminium alloy composites prod uced by a metal infiltration technique was investigated. A pin-on-disc type apparatus was employed for determining the sliding wear rate and the coefficient of friction in a direction normal to the fibre axis. The effects of applied load and volume fraction of fibre on the dry sl iding behaviour were evaluated. The wear rates of the composites were considerably less than that of the aluminium matrix alloy at all appli ed loads. However the friction coefficients of the composites were fou nd to be higher than that of the matrix alloy. Scanning electron micro scopy of the worn surfaces revealed that fibre microfracture was the p redominant mechanism of wear of the composites, while ploughing and de lamination were the operative wear mechanisms of the aluminium alloy m atrix.