DD419镍基单晶高温合金980℃下低周疲劳行为研究  

Study on Low Cycle Fatigue Behavior of DD419 Nickel Base Single Crystal Superalloy at 980℃

作　　者：祝祥 杜晓明[1] 刘纪德[2] ZHU Xiang;DU Xiaoming;LIU Jide(Shenyang Ligong University,Shenyang 110159,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]沈阳理工大学材料科学与工程学院,沈阳110159 [2]中国科学院金属研究所,沈阳110016

出　　处：《沈阳理工大学学报》2023年第4期69-74,共6页Journal of Shenyang Ligong University

基　　金：国家自然科学基金项目(51871221)。

摘　　要：对DD419镍基单晶高温合金在980℃下的低周疲劳行为进行试验研究,并对疲劳数据进行分析,获得该温度下合金疲劳参数。结果表明:该合金低周疲劳变形过程中,弹性变形起主要作用,塑性变形较低;循环应力响应行为以先循环软化、再趋于稳定为主要方式,并且随着应力幅的增加,循环寿命不断降低。低应变幅下,合金的疲劳断裂表现为脆性断裂的特征,并呈现出明显的多源疲劳特征,微观断口形貌的主要特征是出现准解理台阶,可判断准解理断裂是主要的断裂机制。The low-cycle fatigue behavior of DD419 Nickel-based single crystal superalloy at 980℃is experimentally studied and the fatigue data is analyzed to obtain the fatigue parameters.The results show that elastic deformation plays a major role in the process of low cycle fatigue deformation,while plastic deformation is relatively low.The cyclic stress response behavior is cyclic softening first and then stabilizing,and the cyclic life decreases with the increase of stress amplitude.At low strain amplitude,the fatigue fracture of the alloy shows the characteristics of brittle fracture,and presents obvious multi-source fatigue characteristics.The main feature of the microscopic fracture morphology is the presence of quasi-dissociation fracture,by which it can be judged that the quasi-dissociation fracture is the main fracture mechanism.

关 键 词：镍基单晶高温合金 低周疲劳 疲劳寿命 断裂机制 

分 类 号：TU973.254[建筑科学—结构工程]