Method of manufacturing tial alloy and tial alloy

Abstract

A method of manufacturing a TiAl alloy includes a casting step of melting and casting a TiAl alloy raw material which contains 42 at % or more and 45 at % or less of Al, 3 at % or more and 6 at % or less of Nb, 3 at % or more and 6 at % or less of V, 0.1 at % or more and 0.3 at % or less of B, and the balance being Ti and inevitable impurities, a hot forging step of hot forging the cast TiAl alloy by heating the cast TiAl alloy to a temperature range between 1200° C. or higher and 1350° C. or lower, and a thermal treatment step of holding the hot-forged TiAl alloy at a temperature range between 1220° C. or higher and 1300° C. or lower for a hour range between 1 hour or longer and 5 hours or shorter, applying a first thermal treatment to the hot-forged TiAl alloy, cooling the TiAl alloy subjected to the first thermal treatment to a temperature range between 1000° C. or higher and 1100° C. or lower at a cooling rate of 400° C./hour or more, holding the TiAl alloy subjected to the first thermal treatment at a temperature range between 100 ° C. or higher and 1100° C. or lower for a hour range between 1 hour or longer and 4 hours or shorter, applying a second thermal treatment to the TiAl alloy subjected to the first thermal treatment, and rapidly cooling the TiAl alloy subjected to the second thermal treatment.