Study on Microstructure of Ti40 Burn Resistant Titanium Alloy As-Cast

摘要

Ti40 is a highly stabilized β type burn resistant titanium alloy, and always cracks during hot working, especially cogging. Its tensile properties and microstructure as-cast condition were studied by OM, SEM and TEM. The results show that the weakened grain boundary (GB) is a vital factor of brittle intergranular fracture due to the Ti_5Si_3 precipitates in GB and stress concentration at GB for coarse grains and local thermal stress. In addition, the heavy oxidation above 700℃ is another vital reason.