LOW STRAIN PLASTICITY IN A PARTICULATE METAL-MATRIX COMPOSITE

The strengthening that arises when reinforcing an aluminum alloy with approximately equiaxed shaped SiC particles has been measured, with ca reful attention paid to the elastic-plastic transition. The results in dicate that the majority of strengthening develops at low strains, due to the high initial strain hardening rate exhibited by these composit e materials. This can be interpreted in terms of stress partitioning t o the second phase particles during the elastic/plastic transition and beyond. The experimental results are compared with a self-consistent model based on Eshelby's equivalent inclusion method. The model predic tions are in good agreement with experimental data, once effects due t o the inhomogeneous distribution of particles are incorporated.