Fabrication of in situ Ti₂AlN/TiAl composites and their mechanical, friction and wear properties

Ti₂ AlN/TiAl composites were successfully fabricated by the hot-pressing sintering method (reaction hot pressing) using Ti, Al and TiN powders as starting materials. Compared with the TiAl matrix, the hardness, the elastic modulus and the high-temperature compressive strength of Ti₂ AlN/TiAl composites are improved greatly and they are all enhanced by increasing the volume fraction of Ti₂ AlN particles. Friction and wear properties of Ti₂ AlN/TiAl composites were investigated. With the volume fraction of the Ti₂ AlN particles increasing from 20 to 50%, the wear loss of the Ti₂ AlN/TiAl composites decreases a little. The wear resistance of Ti₂ AlN/TiAl composites is a little higher than that of the TiAl alloy at high temperature, the cracking along the phase boundaries and the adhesive spalling are the wear modes of Ti₂ AlN/TiAl composites.