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对Ti-22Al-25Nb(at%)合金在不同相区等温锻造与锻后热处理过程中的组织演变及其对力学性能的影响进行了研究。结果表明,在980℃(B2+α_2+O三相区)、1040℃(α_2+B2两相区)以及1060℃(B2相区)等温锻造并热处理之后,合金的显微组织表现为典型的等轴组织、双态及双尺寸的板条组织,各相的尺寸以及体积分数可以通过热处理制度来控制。合金的力学性能测试表明:双尺寸的板条组织具有较高的室温强度但塑性最低,而等轴组织具有较高的塑性,强度最低。等轴组织的抗蠕变性能最低,双态组织以及双尺寸的板条组织具有相似的抗蠕变性,后两种组织主要以板条组织为主导,板条组织具有比等轴组织更优异的抗蠕变性能。
The microstructure evolution and mechanical properties of Ti-22Al-25Nb (at%) alloy during isothermal forging and forging in different phase regions were studied. The results show that the microstructure of the alloy is typical after isothermal forging and heat treatment at 980 ℃ (B2 + α_2 + O three phase zone), 1040 ℃ (α_2 + B2 two phase zone) and 1060 ℃ (B2 phase zone) Isometric, bimodal and double-size laths, the size and volume fraction of each phase can be controlled by the heat treatment regime. The mechanical properties of the alloy showed that the double-size laths have the highest room temperature strength but the lowest ductility, while the equiaxed ones have the highest ductility and the lowest strength. The isocenter has the lowest creep resistance, the bimodal and the double-size lath have similar creep resistance, the latter two are dominated by lath and the lath are more excellent than the equiaxed ones Creep resistance.