Hot-forged tial-based alloy, method for producing same, and uses for same
AssigneeNational Institute for Materials Science
InventorToshimitsu Tetsui
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Abstract
The present invention provides a TiAl-based alloy, including: Al: 41 to 43 at %; Fe: 0 to 2.5 at %; Ni: 0 to 2.5 at %; Mo: 0 to 2.0 at %; W: 0 to 2.0 at %; Cr: 0 to 4.5 at %; Mn: 0 to 5.5 at %; V: 0 to 10 at %; Nb: 0 to 10 at %; C: 0.3 to 0.7 at %; and a remainder consisting of Ti and inevitable impurities, in which an alloy element parameter “P=(41.5−Al)/3+Fe+Ni+Mo+W+0.5 Cr+0.4 Mn+0.2 V+0.2 Nb—C” is in a composition range of 1.1 to 1.9, and the TiAl-based alloy has a microstructure consisting of a γ phase of 5 to 30 area %, a β phase of 0.5 to 5 area %, and a lamellar structure occupying a remaining part.
Claims5
A method for producing a TiAl-based alloy, the method comprising:
- a step of hot-forging a TiAl-based alloy base material as the temperature of the TiAl-based alloy base material is held in a coexistence temperature range of an α phase and a β phase;
- and
- a heat treating step of holding the TiAl-based alloy material obtained by hot-forging in a temperature range of 1205 to 1245° C. for 0.5 to 5 hours and then cooling the TiAl-based alloy material at a cooling rate of 1 to 10° C./min,
- wherein the TiAl-based alloy base material subjected to the step of hot-forging comprises:
- Al:
- 41 to 43 at %;
- Fe:
- 0 to 2.5 at %;
- Ni:
- 0 to 2.5 at %;
- Mo:
- 0 to 2.0 at %;
- W:
- 0 to 2.0 at %;
- Cr:
- 0 to 4.5 at %;
- Mn:
- 0 to 5.5 at %;
- V:
- 0 to 10 at %;
- Nb:
- 0 to 10 at %;
- C:
- 0.3 to 0.7 at %;
- and
- a remainder consisting of Ti and inevitable impurities,
- an alloy element parameter P obtained by Equation (1) below is in a range of 1.1 to 1.9,
- P=(41.5−Al)/3+Fe+Ni+Mo+W+0.5Cr+0.4Mn+0.2V+0.2Nb—C (1), and
- the produced TiAl-based alloy has a microstructure consisting of a γ phase of 5 to 30 area %, a β phase of 0.5 to 5 area %, and a lamellar structure occupying a remaining part.
A method for producing a TiAl-based alloy, the method comprising:
- a step of hot-forging a TiAl-based alloy base material as the temperature of the TiAl-based alloy base material is held in a coexistence temperature range of an α phase and a β phase;
- and
- a heat treating step of holding the TiAl-based alloy material obtained by hot-forging in a temperature range of 1210 to 1240° C. for 0.75 to 4 hours and then cooling the TiAl-based alloy material at a cooling rate of 1.5 to 8° C./min,
- wherein the TiAl-based alloy base material subjected to the step of hot-forging comprises:
- Al:
- 41.2 to 42.8 at %;
- Fe:
- 0 to 2.0 at %;
- Ni:
- 0 to 2.0 at %;
- Mo:
- 0 to 1.7 at %;
- W:
- 0 to 1.7 at %;
- Cr:
- 0 to 4.0 at %;
- Mn:
- 0 to 5.0 at %;
- V:
- 0 to 8 at %;
- Nb:
- 0 to 8 at %;
- C:
- 0.35 to 0.65 at %;
- and
- a remainder consisting of Ti and inevitable impurities,
- an alloy element parameter P obtained by Equation (1) below is in a range of 1.2 to 1.8,
- P=(41.5−Al)/3+Fe+Ni+Mo+W+0.5Cr+0.4Mn+0.2V+0.2Nb—C (1), and
- the produced TiAl-based alloy has a microstructure consisting of a γ phase of 7 to 25 area %, a β phase of 0.5 to 4.5 area %, and a lamellar structure occupying a remaining part.
A method for producing a TiAl-based alloy, the method comprising:
- a step of hot-forging a TiAl-based alloy base material as the temperature of the TiAl-based alloy base material is held in a coexistence temperature range of an α phase and a β phase;
- and
- a heat treating step of holding the TiAl-based alloy material obtained by hot-forging in a temperature range of 1210 to 1240° C. for 1 to 3 hours and then cooling the TiAl-based alloy material at a cooling rate of 2 to 6° C./min,
- wherein the TiAl-based alloy base material subjected to the step of hot-forging comprises:
- Al:
- 41.2 to 42.8 at %;
- Fe:
- 0 to 2.0 at %;
- Ni:
- 0 to 2.0 at %;
- Mo:
- 0 to 1.7 at %;
- W:
- 0 to 1.7 at %;
- Cr:
- 0 to 4.0 at %;
- Mn:
- 0 to 5.0 at %;
- V:
- 0 to 8 at %;
- Nb:
- 0 to 8 at %;
- C:
- 0.35 to 0.65 at %;
- and
- a remainder consisting of Ti and inevitable impurities,
- an alloy element parameter P obtained by Equation (1) below is in a range of 1.2 to 1.8,
- P=(41.5−Al)/3+Fe+Ni+Mo+W+0.5Cr+0.4Mn+0.2V+0.2Nb—C (1), and
- the produced TiAl-based alloy has a microstructure consisting of a γ phase of 10 to 20 area %, a β phase of 0.5 to 4.0 area %, and a lamellar structure occupying a remaining part.
Dependencies are inferred from the claim text.