一种二代镍基单晶合金750℃原位蠕变行为研究  

In-situ creep behavior study of Ni-based singlecrystal superalloy at 750℃

作　　者：赵京浩 何文玲 唐亮[1] 吕俊霞[1] 王晋 张跃飞[1] 张泽[2] ZHAO Jing-hao;HE Wen-ling;TANG Liang;LJun-xia;WANG Jin;ZHANG Yue-fei;ZHANG Ze(Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124;School of Materials Science and Engineering,Zhejiang University,Hangzhou Zhejiang 310027,China)

机构地区：[1]北京工业大学材料与制造学部,北京100124 [2]浙江大学材料科学与工程学院,浙江杭州310027

出　　处：《电子显微学报》2021年第4期361-366,共6页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金基础科学中心项目(No.51988101);北京市自然科学基金重点项目(No.KZ202110005006).

摘　　要：本文提出了一种基于扫描电镜(SEM)的原位高温蠕变实验研究方法,并在750℃/800 MPa的蠕变条件下,对一种二代镍基单晶高温合金开展蠕变实验,对其微观组织在恒定载荷条件下的演化行为及失效断裂过程进行了原位观察。实验结果表明:该方法在750℃/800 MPa下可稳定进行蠕变实验研究,对镍基单晶合金测量显示实验结果可靠,单晶主要通过位错滑移机制变形,随着应变量增加,样品颈缩程度加剧,蠕变速率随之增加,裂纹首先从孔洞缺陷内部萌生并沿着垂直于应力轴的方向扩展,蠕变后期样品发生瞬间断裂,断面与{111}滑移面相对应,断口呈解理断裂特征。In this paper,a new method of in-situ high-temperature creep experiment based on scanning electron microscopy(SEM)was proposed.Nickel-based single crystal superalloy was studied under the creep conditions of 750℃/800 MPa and the microstructural evolution and the fracture process of superalloy were investigated in detail.The results show that the experimental method is feasible under the creep condition of 750℃/800 MPa.The single crystal superalloy mainly deformed through dislocation slip mechanism.With the increase of strain,the necking of the sample increases,which finally leads to the increase in creep rate.The crack initiated from the shrinkage pores interior and then propagated along the perpendicular direction to the stress axis.In the later stage of creep,the sample broke instantaneously along{111}slip plane.The fracture shows the cleavage fracture characteristics.

关 键 词：原位高温蠕变 镍基单晶高温合金 滑移 颈缩 裂纹 

分 类 号：TG132.3[一般工业技术—材料科学与工程] TG146.15[金属学及工艺—合金]