FRACTURE OF PARTICLES IN A PARTICLE METAL MATRIX COMPOSITE UNDER PLASTIC STRAINING AND ITS EFFECT ON THE YOUNGS MODULUS OF THE COMPOSITE

Fracture of Al2O3 particles in an Al2O3 particle/ aluminum alloy metal matrix composite (MMC) under plastic straining was observed by in-situ tensile testing in a scanning electron microscope. The fracture of larger sized particles was found to be preferred to that of smaller sized ones for a given plastic strain. The Young's modulus (E(c)) of plastically strained MMC was reduced with increase in plastic strain (epsilon-p). The analytical model based on Eshelby's equivalent inclusion method was constructed to explain the relationship between E(c) and epsilon-p, resulting in a good agreement with the experimental results.