Dependence of heating rate in PCAS on microstructures and high temperature deformation properties of γ-TiAl intermetallic alloys

The effect of heating rate in Resistance Sintering on resulting microstructures and properties was not widely explored. For the purpose of obtaining γ-TiAl alloys with fine grains, synthesis of coarse pre-alloyed TiAl powders was carried out with relatively high heating rate on self-built similar sintering device named pulse current auxiliary sintering apparatus (PCAS). The effect of heating rate on microstructures and high temperature ductility was investigated. And high temperature tensile behavior and fractography were compared between the two obtained original microstructures. The results show that relatively high heating rate is beneficial for obtaining fine-grained microstructures. And the resultant intermetallic alloy with equiaxed near gamma microstructures exhibits superplastic properties at relatively low temperature.