高延性TiAl合金的微观组织特征

MICROSTRUCTURE CHARACTERISTICS OF A HIGH DUCTILITY γ-TiAL ALLOY

研究了Ti－33Al－3Cr－0、5Mo合金经包套锻复合热机械处理后的显微组织与力学性能．结果表明，合金经1250℃，4h及控制冷却的最终热处理，可获得以均匀细小等轴γ晶粒为主，含少量β2相和少量α2相的亚双态组织由于晶粒细化和晶界结构改善，该合金室温拉伸延性达到5．07％

The microstructure and mechanical properties of a titanium aluminide alloy, Ti-33Al-3Cr-0.5Mo, under a multi-step thermo-mechanical treatment were studied. A sub-duplex microstructure with fine equiaxial y grains as the major phase and β2, α2 as the minor phases was obtained after final heat treatment at 1250℃, for 4h+controlled cooling.Tensile elongation for the alloy can reach 5.07% at room temperature. The principal reasons for disproving elongation are the refine of grain and improvment of grain boundary structure.