定向凝固镍基高温合金DZ125疲劳裂纹扩展速率研究  

The Study on the Fatigue Crack Growth of Nickel Based Directional Solidification Superalloys DZ125

作　　者：施祎 杨晓光[1,2,3] 杨迪迪 苗国磊 石多奇 SHI Yi;YANG Xiaoguang;YANG Didi;MIAO Guolei;SHI Duoqi(School of Energy and Power Engineering, Beihang University, Beijing 100191;Collaborative Innovation Center for Advanced Aero-Engine, Beijing 100191;School of Aircraft Engineering, Nanchang Hangkong University, Nanchang 330063;Chengdu Holy Industry & Commerce Corp. LTD, Chengdu 611936)

机构地区：[1]北京航空航天大学能源与动力工程学院,北京100191 [2]先进航空发动机协同创新中心,北京100191 [3]南昌航空航天大学飞行器工程学院,南昌330063 [4]成都航利(集团)实业有限公司,成都611936

出　　处：《机械工程学报》2019年第13期45-52,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51775019);国家重点基础研究发展计划(2015CB057401)资助项目

摘　　要：选择定向凝固镍基高温合金DZ125为研究对象,选用紧凑拉伸(Compact tension,CT)试样,并根据ASTM-E647标准采用卸载柔度法分别开展室温以及高温(760℃、850℃)条件下的疲劳裂纹扩展试验。主要研究了温度以及材料取向对于裂纹扩展速率的影响,试验结果表明:高温使得裂纹扩展速率明显增加;但材料取向在高温下对裂纹扩展速率的影响较弱。同时高温导致部分试样裂纹扩展路径出现不严格垂直于载荷施加方向的现象。最后结合Paris扩展模型,拟合相关结果,建立系数C以及指数m与温度的关系,进一步比较讨论温度以及取向对DZ125裂纹扩展影响。The nickel based directional solidification superalloys DZ125 is chosen as the study object. The compact tension (CT) specimens are used and the fatigue crack growth experiments are conducted at room temperature and high temperature (760℃ and 850℃)respectively based on the unloading compliance method according to the ASTM-E647 standard. The influence of temperature and material orientation on fatigue crack growth rate are mainly investigated. The test results show that:elevated temperature increases the crack growth rate significantly, while the influence of material orientation on the rate is limited at elevated temperature. Meanwhile high temperature results in the deflection in some of the specimens, which means the crack growth path was not perpendicular to the loading direction. Finally, combined with the Paris propagation model, the relationship of coefficient C and exponent m between the temperature were established by regressing the corresponding results to further discuss the temperature and orientation effect.

关 键 词：定向凝固 疲劳 裂纹扩展速率 柔度法 高温 

分 类 号：V231[航空宇航科学与技术—航空宇航推进理论与工程]