【摘要】 研制出1种细晶的8.5Nb-TiAl基合金,化学成分为Ti-45Al-8.5Nb-0.3W-0.3B（TAWBY）,铸态组织的晶粒度约为25μm。合金中含有一定量的B₂+ω相,B₂相和ω相的位相关系（110）_B2//（0001）_ω和[111]_B2//[110]_ω。同时,对TAWBY合金的变形试样进行了1250℃,1h和1310℃,0.5h真空退火处理,分别获得了DP和FL组织。对2种组织的试样进行了室、高温拉伸和三点弯曲K_IC测试,分析了变形TAWBY合金与K5合金等第3代TiAl基合金的力学性能。结果表明,在760℃～870℃下,高温拉伸性能己达到第3代TiAl基合金的性能。更多还原

【Abstract】 In order to keep the first step in the aeronautics and astronautics industry, it is necessary and essential to develop high strength and high temperature resistance TiAl based alloy containing high Nb. To breakup the primary as-cast microstructures and refine the grains is the method improving the combined propertied. A new alloy whose nominal chemical composition is Ti-45Al-8.5Nb-0.3W-0.3B-0.05Y at % (TAWBY), was developed with as-cast grains as the size of 25μm. B2 and ωphase in this alloy take the orientation relationship as (110)B2// (0001)ω and [111]B2// [1120]ω. The as-annealing specimens were conducted with tensile tests and three-point wending tests after heat treatment, 1 250℃, 1h and 1 310℃, 0.5h vacuums annealing, with DP and FL microstructures. Compared with mechanical properties for TAWBY alloy and K5 alloy, TAWBY alloy has already owned the best properties. Under the same condition, TAWBY alloy exhibits the perfect properties of K5 alloy and so on.更多还原