镍基单晶高温合金低周疲劳不同阶段微观机制的研究  

Low cycle fatigue mechanism under different stagesof nickel base single crystal superalloy

作　　者：骆红云[1] 陈其武 刘洁 LUO Hongyun;CHEN Qiwu;LIU Jie(School of Material Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《长春工业大学学报》2022年第4期324-331,共8页Journal of Changchun University of Technology

基　　金：国家科技重大专项(J2019-Ⅵ-0022-0138)。

摘　　要：研究了[001]取向第二代镍基单晶高温合金760℃下的低周疲劳行为,主要通过低周疲劳断口形貌和位错组态等研究镍基单晶高温合金不同阶段的低周疲劳机制。镍基单晶高温合金低周疲劳的裂纹萌生区,主要是<11^(-)0>,<020>和<100>方向的位错在γ′相内部增殖和运动;在扩展阶段存在位错大量运动,部分区域80%可观察到位错网;进入瞬断阶段,试样承受的应力非常大,开动的滑移系数量多,滑移方式多样,除了在{111}滑移面内进行滑移外,还有交滑移和攀移等方式,形成连续的阶梯台阶结构。The low cycle fatigue behavior at 760℃of[001]oriented nickel base single crystal superalloy was studied,fracture morphology and dislocation configuration of the samples under low cycle fatigue condition were investigated and the mechanism of different fatigue stages of nickel base single crystal superalloy was studied.At fatigue crack initiation stage of nickel base single crystal superalloy,the dislocations in the<11^(-)0>,<020>and<100>direction are mainly multiplicated and moved in theγ′phase internal propagation.There were a lot of dislocations in the expansion stage,and dislocation tangle could be observed at more than 80%of the fracture areas.In the instantaneous fault stage,the stress of the sample is very large,resulting in activating of more slipping systems.In addition to sliding in{111}slip plane,there are also cross sliding and climbing,which forming a continuous step structure.

关 键 词：镍基单晶高温合金 低周疲劳 位错组态 滑移 

分 类 号：TG113.255[金属学及工艺—物理冶金]