Nd对一种近α型高温钛合金热稳定性的影响
Effect of Nd on Thermal Stability of Near-α Titanium Alloy
丁蓓蓓, 李伯龙, 韩 鹏, 聂祚仁
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作者单位：北京工业大学 材料学院, 北京 100124
中文关键字：稀土Nd； 高温钛合金； 热稳定性
英文关键字：rare earth Nd; high temperature titanium alloy; thermal stability
中文摘要：采用光学显微镜、透射电镜以及扫描电镜观察分析了不含Nd和含0.8wt%Nd(简化为0.8Nd)的两种高温钛合金热暴露前后微观组织变化和拉伸断口形貌。结果表明，稀土Nd的添加可明显提高高温钛合金室温及高温拉伸性能，并有效改善合金热稳定性。其主要作用机理为：Nd在合金中以含有O、Nd、Sn三种元素为主的颗粒存在，弥散分布在合金中，细化了晶粒并提高合金强度，同时又降低了合金基体的氧含量，从而减小了基体的Al当量，改善合金热稳定性。
英文摘要：The tensile properties of two high temperature titanium alloys (one without Nd and the other with 0.8wt%Nd) after high temperature exposure were investigated. The microstructure variation of two alloys and morphologies of fracture were observed by OM, TEM and SEM. The results show that the tensile property and thermal stability of the alloy with 0.8at%Nd improve compared with the alloy without Nd. This might be attributed to smaller grain size caused by the rare earth phases which are composed of Nd, Sn and O. They can hinder the movement of grain boundaries and decrease the O content in the alloy, which can help improve the thermal stability.