一种单晶合金的高温循环断裂变形行为  

High Temperature Cyclic Fracture and Deformation Behavior of a Ni-Base Single Crystal Superalloy

作　　者：于金江[1] 金天文 谢君[1] 孙晓峰[1] YU Jin-jiang;JIN Tian-wen;XIE Jun;SUN Xiao-feng(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China;AECC South Industry Co.,Ltd.,Zhuzhou 412002,Hunan,China)

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]中国航发南方工业有限公司,湖南株洲412002

出　　处：《铸造》2021年第2期189-193,共5页Foundry

基　　金：国家自然科学基金(51771191,51971214)。

摘　　要：系统研究了DD499单晶合金950℃应变控制的低周疲劳循环断裂变形行为。研究表明,高温氧化不但加速了裂纹在试样表面萌生,而且也促进了裂纹沿[110]方向扩展,合金低周疲劳的失效可归因于氧化、蠕变和疲劳破坏累积的共同作用结果。950℃循环应力响应为位错之间、位错与γ'沉淀相颗粒之间、位错与碳化物之间的交互作用的共同强化结果。950℃低周疲劳变形机制由位错剪切向位错攀移进行转变。Low-cycle fatigue(LCF)cyclic fracture and deformation behaviors were systemically investigated at 950℃on DD499 single crystal superalloy.It is shown that high temperature oxidation not only accelerates the initiation of crack at the surface,but also promotes the crack propagation along[110]direction.The low-cycle fatigue failure occurs under the combined action of oxidation,creep and fatigue.The cyclic stress response behavior at 950℃can be taken as the result of interactions between dislocation-dislocation,dislocation-γ′precipitate,dislocations and carbides.Low cycle fatigue deformation mechanism at 950℃is transiting from dislocations shearing to dislocation climb.

关 键 词：镍基单晶合金 低周疲劳 等温循环变形 循环应力响应 

分 类 号：TG142.1[一般工业技术—材料科学与工程]