Preparation And Properties Of Ti₃AlC₂ & Ti₃AlC₂/Cu Composites

The ternary compound Ti₃AlC₂ exhibits an excellent combination of good properties of ceramics and metals, and it can be used as a new enforcement phase for cooper matrix composites. A batch of high purity Ti₃AlC₂ powder was synthesized by pressureless reaction sintering, which used Sn as the additive agent. Meanwhile Ti₃AlC₂ bulks were fabricated by hot-pressing a mixture of Ti, Al, and graphite powders with and without Sn additive. The results showed that no high purity Ti₃AlC₂ bulk was sintered at different temperature without Sn additive, and the impurity phase TiC influenced the properties of Ti₃AlC₂ bulks. Whereas the addition of Sn additive led to high purity bulks, the electrical resistivity of the Ti₃AlC₂ bulk was 0.3656μΩ·m, the flexural strength was 340MPa. Ti₃AlC₂/Cu composites were prepared by overlay infiltration dipping infiltration and hot pressing processing respectively. A spot of pore could be fund in the Ti₃AlC₂/Cu composites fabricated by overlay infiltration. Longer infiltration time helped much more Cu to infiltrate into Ti₃AlC₂ green body, and result in better electrical conductivity. The green body should be strong enough for the dipping infiltration processing. The composites fabricated by hot pressing processing possessed good uniformity and compactability, the highest flexural strength of the composites was 1033MPa when the Ti₃AlC₂ content was 30 vol %, the fracture mode was changed from ductile to brittle with the increase in the content of Ti₃AlC₂, as well as the room temperature electrical resistivity of the composites was increased linearly.