Grain refining of Er added to Ti-22Al-25Nb alloy and morphology of erbium precipitates

作     者：Jing-Ru Dai Hui-Min Lu Zhi-Jin Cai Chao An 

作者机构：School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2013年第32卷第1期

页      面：5-11页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：financially supported by the Science and Technology Ministry of China to the National High Technology "863" Project (No. 2012AA062302) 

主　　题：Ti2A1Nb-based alloys Rare earth erbium(Er) Microstructure Erbium precipitates 

摘      要：In order to investigate the effect of erbium （Er） on the microstructure of orthorhombic Ti2A1Nb-based alloys, four testing alloys were prepared by adding differ- ent contents of the rare earth metal Er to Ti-22A1-25Nb alloy and optical microscopy, X-ray diffraction, scanning electron microscopy, electron probe microanalysis, energy- dispersive spectrometry, and transmission electron microscopy were used. The results show that the addition of Er is capable of grain refining and the refinement effect is more obvious with increasing content of Er. The Er203 dispersoids formed by internal oxidation and A13Er com- pound particles are observed in Er-doped alloys and the number of Er precipitates is increased with increasing Er addition. It is likely that the solubility of Er in the Ti2A1Nb alloy is very low and Er precipitates tend to segregate at grain boundaries, which together with the surface activity of rare earth elements is supposed to decrease the prior B2 grain size of Ti-22A1-25Nb alloy effectively.