The effect of processing route and reinforcement geometry on isothermal creep behaviour of particulate and short fibre MMCs

Isothermal creep tests were performed on discontinuously reinforced Al composites at 270 and 300°C. Axial and transverse strain were monitored simultaneously during testing using laser scanning extensometry. Damage mechanisms were found to dominate the creep behaviour rather than load transfer considerations. The effect of powder-processing versus squeeze infiltration on composite creep behaviour was characterised. The effect of interfacial bond strength was investigated by comparing carbon and Saffil (alumina) short fibre reinforcements. The effect of reinforcement shape, size and aspect ratio was also investigated by comparing short fibre, whisker and particulate reinforcements.