The effect of reinforcement size on the creep strength of intermetallic matrix composites

Abstract

The creep strengthening of intermetallic materials by reinforcements is shown to be limited owing to diffusional matter transport along the reinforcement/matrix interface. In order to avoid strength reduction by fast diffusion, a critical reinforcement size has to be exceeded which depends on the loading conditions (temperature, strain rate) of the composite. The required particle dimensions are identified in this article, comparing the rate of diffusive matter transport with the applied strain rate. Model predictions are shown to be in good agreement with experimental data obtained for γ-TiAl reinforced with Ti2AlC platelets.