CMSX-4单晶高温合金在不同温度下的低周疲劳行为  

Low Cycle Fatigue Behavior of Single-Crystal Superalloy CMSX-4 at Different Temperatures

作　　者：赵玉娟 玄伟东 张翔宇 戴睿卿 李俊杰 韩东宇 丁彪 任忠鸣 Zhao Yujuan;Xuan Weidong;Zhang Xiangyu;Dai Ruiqing;Li Junjie;Han Dongyu;Ding Biao;Ren Zhongming(State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy,School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料科学与工程学院省部共建高品质特殊钢冶金与制备国家重点实验室,上海市钢铁冶金新技术应用重点实验室,上海200444

出　　处：《稀有金属材料与工程》2022年第11期4363-4368,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(92060104);国家科学技术重大项目(2017-Ⅶ-0008-0102);上海市科学技术委员会(20511107700)。

摘　　要：研究了单晶高温合金CMSX-4在中温760℃和高温950℃下的低周疲劳行为。结果表明:在760℃下合金具有较长的疲劳寿命和较高的疲劳强度,断面高度差大并与应力轴方向呈45°角,裂纹沿{111}面扩展;而在950℃下合金具有较短的疲劳寿命和较低的疲劳强度,断面与应力轴垂直,裂纹沿{001}面扩展。低周疲劳断口的扫描电镜结果表明,760℃试样表面的微孔是主要的疲劳源,而950℃试样表面的氧化层是主要的疲劳源且呈多源开裂。低周疲劳断口的透射电镜结果表明,中温760℃下位错的变形机制包括平面滑移和波状滑移;而高温950℃下位错主要通过交滑移和攀移进行运动。The low cycle fatigue behaviors of single-crystal superalloy CMSX-4 were investigated at 760 and 950℃.At 760℃,specimens have longer fatigue lives and higher strength under higher strain amplitude.The fracture sections of specimens at 760℃have a large height difference with an angle of 45°to the stress axis direction,and the cracks expand along the{111}plane.While the fracture sections of specimens at 950℃are perpendicular to the stress axis,and the cracks expand along the{001}plane.Scanning electron microscope was employed to analyze the fatigue fracture,and it is found that the micropore near the surface of specimens at 760℃is the main fatigue source,while the fatigue cracks originated from the oxide layer near the surface of specimens at 950℃is the main fatigue source and it shows multiple sources of cracking.Transmission electron microscope was employed to analyze the dislocation motion modes.The deformation mechanism of low cycle fatigue at 760℃includes planar slip and wavy slip.Whereas,the dislocation at 950℃mainly moves by cross-slip and a process of gliding and climbing.

关 键 词：单晶高温合金 低周疲劳 疲劳断口 位错 

分 类 号：TG132.33[一般工业技术—材料科学与工程]