Microstructural Instability of an Experimental Nickel-Based Single-Crystal Superalloy

作     者：Bin Yin Guang Xie Xiangwei Jiang Shaohua Zhang Wei Zheng Langhong Lou Bin Yin;Guang Xie;Xiangwei Jiang;Shaohua Zhang;Wei Zheng;Langhong Lou

作者机构：Superalloys DivisionInstitute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2020年第33卷第10期

页      面：1433-1441页

核心收录：

学科分类：0817[工学-化学工程与技术] 0806[工学-冶金工程] 08[工学] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0802[工学-机械工程] 0703[理学-化学] 0811[工学-控制科学与工程] 

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51771204,U1732131,51911530154,91860201 and 51631008) the National Science and Technology Major Project(No.2017-Ⅶ-0008-0101) 

主　　题：Nickel-based single-crystal superalloy Topologically close-packed(TCP)phases Segregation Eutectic 

摘      要：Microstructural instability with the precipitation of topologically close-packed(TCP)phases of an experimental nickel-based single-crystal superalloy has been investigated.A significant amount of σ phases are distinguished in the interdendritic region of the as-cast samples after thermal exposure at 900℃ for 1000 ***σphases are preferentially precipitated at the periphery of coarse γ/γ′eutectic,and their morphological evolution from needles to granules is *** analysis suggests that the local segregation of Cr and Ti at the periphery of coarse γ/γ′eutectic accounts for the formation ofσphases in the as-cast *** heat treatment with low solution temperature and short holding time,the dendritic segregation of alloying elements(i.e.,W,Re,Ti and Ta)and the volume fraction of γ′phase in the interdendritic region are similar to that of the as-cast ***,no TCP phases are present in the interdendritic region of the heat-treated samples after thermal exposure,which is primarily ascribed to the elimination of local segregation of Cr and Ti near the coarse γ/γ′***,small quantities ofμphases are precipitated in the secondary dendrite arm near the interdendritic region after thermal exposure,due to the increased volume fraction ofγ′phase and the concomitant enrichment of W and Re in theγmatrix.