US 12,276,015 B2
Method of manufacturing TiAl alloy and TiAl alloy
Keiji Kubushiro, Tokyo (JP)
Assigned to IHI Corporation, Tokyo (JP)
Filed by IHI Corporation, Tokyo (JP)
Filed on Oct. 13, 2021, as Appl. No. 17/450,724.
Application 17/450,724 is a continuation of application No. PCT/JP2020/012032, filed on Mar. 18, 2020.
Claims priority of application No. 2019-096653 (JP), filed on May 23, 2019.
Prior Publication US 2022/0205075 A1, Jun. 30, 2022
Int. Cl. C22F 1/18 (2006.01); C22C 1/02 (2006.01); C22C 14/00 (2006.01)
CPC C22F 1/183 (2013.01) [C22C 1/02 (2013.01); C22C 14/00 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A method of manufacturing a TiAl alloy, comprising:
a casting step of melting and casting a TiAl alloy raw material which consists of 43 at % of Al, 4 at % of Nb, 5 at % of V, 0.2 at % 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 1200° C., and
a thermal treatment step of applying a first thermal treatment to the hot-forged TiAl alloy by holding the hot-forged TiAl alloy at a temperature of 1250° C. for 2.5 to 3.5 hours, cooling the TiAl alloy subjected to the first thermal treatment to a temperature of 1000° C. at a cooling rate of 400° C./hour or more, applying a second thermal treatment to the TiAl alloy subjected to the first thermal treatment by holding the TiAl alloy subjected to the first thermal treatment at a temperature of 1000° C. for 2 to 4 hours, and rapidly cooling the TiAl alloy subjected to the second thermal treatment.