Field-Assisted Sintering on Microstructural Evolution and Properties of TiAl Intermetallic Alloys

The addition of minor fractions of grain refiners commonly improves the mechanical properties of TiAl intermetallic alloys. In this study, Ti-36 wt.% Al powders were consolidated using a field-assisted sintering technique without adding grain refiners. Various temperatures (650–1300 °C) and pressures (14–50 MPa) were used to elucidate the structure–property relationship. An intermetallic of 99.9% relative density with a corresponding microhardness value of 327 ± 6 HV 0.5 was achieved for alloys sintered at 1300 °C and 16 MPa. Alloys sintered at 1100 °C displayed a microstructure consisting of citrus Ti-rich grains, while a duplex microstructure consisting of γ -TiAl + α 2 -Ti 3 Al lamellae, and γ -TiAl phases were observed at 1300 °C.