Creep deformation characteristics of discontinuously reinforced aluminium-matrix composites

Recent developments in the study of creep behaviour of discontinuously reinforced aluminium-matrix composites (DRAMCs) at elevated temperatures are reviewed in this paper. These include the shapes of the creep curves, the origin and characteristics of the threshold stress, the creep strengthening of the DRAMCs, the nature of the rate-controlling processes, the effect of cyclic stress, and creep rupture. The DRAMCs exhibit high values of apparent stress exponent and apparent activation energy for creep. Incorporation of the threshold stress into analyses reduces the high and variable values of apparent stress exponent and activation energy to those anticipated from the creep of pure metals and solid-solution alloys. This indicates that the creep in the DRAMCs is controlled by the plastic flow in the matrix materials. (C) 2001 Elsevier Science Ltd. All rights reserved.