Compressive deformation behavior of TiC/AZ91D composites at elevated temperatures

In situ reactive infiltration technique was utilized to synthesis TiC particulate-reinforced magnesium matrix composites (TiC/AZ91D). The hot compressive behavior of as fabricated composites was studied at strain rates (epsilon) over dot 10(-3) - 10(-1) s(-1) and at temperatures of 573-723 K. The strain rate sensitivity exponent (m), apparent activation energy (Q) and their relations with TiC content and temperature were calculated and analyzed according to the true stress-true strain curves. The results show that the compressive flow stress of the composites increases with increasing the TiC content. For the same TiC content, the flow stress decreases with elevating deformation temperatures or with decreasing the initial strain rates. The m value increases with increasing temperature and at the same deformation temperature and strain rate, the m value increases with increasing the TiC content. The Q value depends on the deformation temperature, strain rate and TiC content and its distribution, and the composites exhibit different deformation mechanisms at elevated temperatures.