Low-Cycle Fatigue Crack Initiation Behavior of Nickel-Based Single Crystal Superalloy

作     者：Zhang Jingang Liu Xinling Chen Xing Li Zhen Li Leyu Liu Changkui 张金刚;刘新灵;陈星;李振;李乐宇;刘昌奎

作者机构：Failure Analysis Center of Aero Engine Corporation of ChinaAECC Beijing Institute of Aeronautical MaterialsBeijing 100095China Beijing Key Laboratory of Aeronautical Materials Testing and EvaluationBeijing 100095China 

出 版 物：《稀有金属材料与工程》 (Rare Metal Materials and Engineering)

年 卷 期：2024年第53卷第9期

页      面：2458-2467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：National Science and Technology Major Project(J2019-VI-0022-0138) 

主　　题：crack initiation low-cycle fatigue single crystal superalloy casting defects dislocation density 

摘      要：Low-cycle fatigue crack initiation behavior of nickel-based single crystal superalloy at 530℃ was *** show that the behavior of crack initiation is closely related to the maximum *** the maximum strain is 2.0%,the fatigue crack is originated at the position of persistent slip bands on the surface of specimen,which is located on the{111}slip *** defects are observed at the crack initiation *** the maximum strain is lower than 1.6%,the cracks are initiated at the casting defects on sub-surface or at interior of the *** casting defects are located on the{100}slip plane vertical to the axial *** crack is initiated along the{100}slip plane and then expanded along different{111}slip planes after a short stage of *** the maximum strain decreases,the position of crack initiation gradually changes from the surface to the ***,the secondary cracks extending inward along the fracture surface appear in the crack initiation area,and there is obvious stress concentration near the secondary *** dislocation density is high near the fracture surface in the crack initiation zone,where a lot of dislocations cutting into the γ phase *** oxide layer of 50‒100 nm is presented on the fracture surface,and Ni,Al,Cr and Co elements are mainly segregated into the oxide layer of the surface.