Effect of TiC content on the microstructure and mechanical properties of Ti_3AlC_2/Al_2O_3 in situ composites synthesized by hot pressing

摘要

The Ti_3AlC_2/Al_2O_3 in situ composites were successfully synthesized from the system of Ti-TiC-Al-TiO_2 by reactive hot pressing at 1350 °C. The effect of TiC content on the phase composition, microstructure and mechanical properties were investigated in detail. The results indicate that the fabricated products possess the highest purity as the TiC contents reduce to 90 % of its theoretical content. This deviation is mainly attributed to the decomposition of Ti_3AlC_2 and vaporization of Al at high temperatures. The effect of TiC content on the fracture toughness, flexural strength, Vickers hardness of Ti_3AlC_2/Al_2O_3 composites was also discussed in detail.