Tial alloy for forging, tial alloy material, and method for producing tial alloy material

Abstract

A TiAl alloy may be suitable for forging and may be used to produce a TiAl alloy material having excellent oxidation resistance, high-temperature creep strength, excellent hot forgeability, and can be subjected to die forging. The TiAl alloy may contain, in atomic percentage: Ti; Al in a range of from 42.0 to 43.6%; Cu in a range of from 0.5 to 2.0%; and Nb in a range of from 3.0 to 7.0%; and unavoidable impurities.

1 . A TiAl alloy suitable for forging, comprising, in atomic percentage:
 Ti;   Al in a range of from 42.0 to 43.6%;   Cu in a range of from 0.5 to 2.0%;   Nb in a range of from 3.0 to 7.0%; and   unavoidable impurities.   
     
     
         2 . A TiAl alloy material, comprising, in atomic percentage:
 Al in a range of from 42.0 to 43.6%;   Cu in a range of from 0.5 to 2.0%;   Nb in a range of from 3.0 to 7.0%; and   unavoidable impurities,   wherein an area ratio of a β phase of the TiAl alloy material is in a range of from 0.5 to 15.0%.   
     
     
         3 . A method for manufacturing a TiAl alloy material, the method comprising:
 forging a TiAl alloy suitable for forging to obtain a forged material, the TiAl alloy comprising, as atomic percentage, Ti; Al in a range of from 42.0 to 43.6%; Cu in a range of from 0.5 to 2.0%; Nb in a range of from 3.0 to 7.0%; and unavoidable impurities; and   heating the forged material first at a temperature in a range of from 1200 to 1350° C., and subsequently at a temperature in a range of from 850 to 1000° C.   
     
     
         4 . The TiAl alloy of  claim 1 , comprising the Al in a range of from 42.5 to 43.5 atom. %. 
     
     
         5 . The TiAl alloy of  claim 1 , comprising the Cu in a range of from 0.7 to 1.2 atom. %. 
     
     
         6 . The TiAl alloy of  claim 1 , comprising the Nb in a range of from 4.5 to 6.0 atom. %. 
     
     
         7 . The TiAl alloy of  claim 1 , comprising, in atomic percentage:
 the Al in a range of from 42.5 to 43.5%;   the Cu in a range of from 0.7 to 1.2%; and   the Nb in a range of from 4.5 to 6.0%.   
     
     
         8 . The TiAl alloy of  claim 2 , comprising the Al in a range of from 42.5 to 43.5 atom. %. 
     
     
         9 . The TiAl alloy of  claim 2 , comprising the Cu in a range of from 0.7 to 1.2 atom. %. 
     
     
         10 . The TiAl alloy of  claim 1 , comprising the Nb in a range of from 4.5 to 6.0 atom. %. 
     
     
         11 . The TiAl alloy of  claim 1 , comprising, in atomic percentage:
 the Al in a range of from 42.5 to 43.5%;   the Cu in a range of from 0.7 to 1.2%; and   the Nb in a range of from 4.5 to 6.0%.   
     
     
         12 . The method of  claim 3 , wherein the TiAl alloy material has an area ratio of a β phase in a range of from 0.5 to 15.0%. 
     
     
         13 . The method of  claim 3 , wherein the heating at the temperature of 850° C. to 1000° C. is 1 hour at 950° C. or 3 hours at 900° C. 
     
     
         14 . The TiAl alloy of  claim 1 , consisting of the Ti, the Al, the Cu, the Nb, and the unavoidable impurities. 
     
     
         15 . The TiAl alloy of  claim 2 , consisting of the Ti, the Al, the Cu, the Nb, and the unavoidable impurities.