(中国科学院 金属研究所，沈阳 110016)
摘 要: 研究了不同Mo含量的Ti-6Al-2Sn-4Zr-xMo (x=2, 4, 6)合金在β单相区的晶粒长大行为，分析了Mo元素对钛合金显微组织及力学性能的影响。结果表明：Mo含量高的合金，晶界迁移激活能大，晶粒长大速度慢。对于不同Mo含量的合金，其晶粒尺寸的离散程度均随晶粒长大而增大。当合金的平均晶粒尺寸相同时，晶粒尺寸离散程度相近。当冷却速率相同时，Mo含量高的合金，其晶粒内部的α集束和片层细小；β晶粒越大α片层越小，这种趋势在Mo含量高的合金中更加明显。另外，Mo含量升高会降低合金的弹性模量，提高合金的断裂强度。
关键字: 钛合金；Mo；晶粒尺寸；α集束；α片层
（Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China）
Abstract:The grain growth behaviour of Ti-6Al-2Sn-4Zr-xMo (x=2, 4, 6) alloys was investigated and the effects of Mo element on the microstructures and mechanical properties were analyzed. The results show that the alloy with high Mo content has low grain growth rate because of the high activation energy for the grain boundary migration. For the alloys with different Mo contents, the levels of grain size dispersion all increase with the grain growth, and when they have the same average grain size their grain size dispersion levels are also similar. For the alloys with the same cooling rate from β phase field, higher Mo content alloy has smaller α colonies and lamellaes, larger β grain size has smaller α lamellaes which is more obvious for the alloy with high Mo content. Moreover, the alloy has the lower elastic modulus and higher tensile strength with the increasing Mo content.
Key words: Ti alloy; Mo; grain size; α colony; α lamellae
