Solid solubility extension and microstructure evolution of cast zirconium yttrium alloy

作     者：Jia-Qing Peng Yang Chen Guo-Qing Yan Ming Wu Li-Jun Wang Jing-She Li 

作者机构：Division of Rare Metals Metallurgy and MaterialsGeneral Research Institute for Nonferrous Metals School of Metallurgical and Ecological EngineeringUniversity of Science and Technology Beijing 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2016年第35卷第4期

页      面：325-330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 National Natural Science Foundation of China(No.5140041034) 

主　　题：Zirconium alloy Yttrium addition Solidsolubility extension Microstructure 

摘      要：Yttrium addition can improve the oxidation resistance, mitigate hydrogen embrittlement and thus enhance the mechanical properties of the zirconium alloy. To study solid solubility extension of yttrium in zirconium alloy, the lattice parameters of ：t-Zr phase in Zr-Y alloy were accurately determined by X-ray diffraction （XRD）. Yttrium exhibits solid solubility extension in the cast zirconium alloy which forms a metastable supersaturated solid solution with solubility limit of around 3 wt%. The effect of yttrium and thermal treatment on the microstructure of the alloys was investigated by optical microscopy （OM） and scanning electron microscope （SEM）. The cast Zr-Y alloy shows a normal polycrys- talline structure with dispersed α-Y particles when Y content is lower than 4 wt%, while the alloy shows a eutectic structure with dendrites formation when the Y content is higher. Yttrium exhibits a strong grain refining effect on zirconium alloy and precipitates from the metastable supersaturated Zr matrix after annealing at 700 and 900 ℃.