On Strain-Rate Sensitivity of Metal Matrices Reinforced with Ceramic Particles

Abstract

A micromechanics study is carried out for the high strain-rate deformation of ceramic particle reinforced metal matrix composites. The ceramic particles are taken to be elastic, equal-sized, spherical, and uniformly distributed in the matrix. The stress-strain behavior of the matrix material is assumed to be elastic-perfectly plastic or power-law strain hardening of the Ramberg-Osgood type, coupled with power-law strain rate hardening. Systematic predictions are made of the composite flow stress as determined by inclusion volume fraction, the applied strain rate, and the strain hardening exponent and strain rate sensitivity of the matrix. A simple constitutive expression is obtained which allows one to predict readily the rate-dependent plastic flow behavior of the composite. Comparison between the model predictions and experimental measurements for the strain rate dependence of an A1/A12O3 composite shows good agreement.KeywordsFlow StressMatrix MaterialActa MetallCeramic ParticleParticle Volume FractionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.