【摘要】 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+α₂+O三相区）、1040℃（α₂+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。更多还原

【Abstract】 The microstructure evolution and mechanical property of Ti-22Al-25Nb（at%） alloy by different phase region isothermal forging and heat treatment were studied. The results indicate that as the isothermally forging temperature increases from 980 °C（α₂+O+B2 three phase region） to 1040 °C（α₂+B2 two phase region） to 1060 °C（B2 phase region）, the microstructures of alloys are equiaxed microstructure, duplex microstructure, and bimodal size lamellar O microstructure. The size and volume fraction of each phase can be controlled by heat-treatment schedule. The mechanical properties of alloys show that bimodal size lamellar O microstructure has the highest strength but the worst ductility; however, the equiaxed microstructure has the highest ductility but the lowest strength. The equiaxed microstructure has the worst creep resistance, while the duplex microstructure and the bimodal size lamellar O microstructure have similar creep resistance, because they are both mainly lamellar structure, which possess better creep resistance than the equiaxed microstructure.更多还原