Aspects of strengthening and work hardening in particulate metal matrix composites

Abstract

Numerous theoretical models have been developed to understand the cause of strengthening in metal matrix composites (MMCs) in terms of their microstructural characteristics. However, it is often difficult to provide a quantitative analysis of strengthening behavior in these materials and there is no consensus on the mechanism responsible for strength increase. In recent years, very few studies have been reported on the work hardening behavior of MMCs and therefore, there is a need for a proper understanding of the work hardening behavior of such composite materials. In view of this necessity, a modified strengthening model has been developed, which is based on the model proposed by Wu and Lavernia. This leads to a strength dependence of particle shape, size, volume fraction and also the strain. The model has been used to predict the yield strength (0.2% proof stress) of few Al6061-SiC particulate MMCs and these results are compared with experimentally determined values to check the validity of the present model. Finally, the work hardening characteristic has been studied theoretically and compared with experimental data.