Abstract In present work, the effect of Y2O3 on tensile properties and fracture behavior of Ti-48Al-2Cr-2Nb alloy at elevated temperature was investigated. The alloys were successively fabricated by induction skull melting. The results revealed that tensile strength and elongation of the Y2O3-bearing TiAl alloy both improved evidently at elevated temperature. The TiAl-Y2O3 alloy still exhibited considerable mechanical properties with ultimate tensile strength of 587 MPa and elongation of 23.0% at 850 °C. Simultaneously, the brittle-ductile transition temperature of the TiAl-Y2O3 alloy reduced about 50 °C, which displayed the toughness fracture feature with dimples firstly at 800 °C. In addition, Y2O3 could effectively prevent the movement of dislocation and promote the nucleation of deformation twins during tensile testing. The excellent properties could be attributed to the compounding effect of fine lamellar phase, increasing content of γ phase and dispersive Y2O3 particles.

中文翻译：

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含Y2O3的Ti-48Al-2Cr-2Nb合金的高温拉伸性能和断裂行为

摘要 在目前的工作中，研究了Y2O3 对Ti-48Al-2Cr-2Nb 合金高温拉伸性能和断裂行为的影响。这些合金依次通过感应头壳熔化法制造。结果表明，含Y2O3 的TiAl 合金的抗拉强度和延伸率在升高的温度下均有明显提高。TiAl-Y2O3 合金仍然表现出可观的机械性能，极限抗拉强度为 587 MPa，850 °C 下的伸长率为 23.0%。同时，TiAl-Y2O3 合金的脆-韧转变温度降低了约 50 °C，在 800 °C 时首先表现出带凹坑的韧性断裂特征。此外，Y2O3在拉伸试验中可以有效地阻止位错运动并促进变形孪晶的形核。