摘要
通过室温低周疲劳(LCF)试验研究了Cu-Cr-Zr合金的低周疲劳性能和循环变形行为,利用电子背散射衍射、透射电镜和扫描电镜分别分析了合金循环变形前后的微观结构和疲劳断口。结果表明:Cu-Cr-Zr合金的弹性应变幅、塑性应变幅与断裂时的循环周次之间的关系可分别用Basquin和Coffin-Manson公式表示。Cu-Cr-Zr合金在高外加总应变幅(Δεt/2=0. 6%)的疲劳变形后期会出现循环硬化现象,循环变形组织为位错墙、位错团簇、亚结构胞状组织的混合结构,并且观察到了孪晶的形成。此外,所选材料在外加总应变幅为0. 4%时的疲劳断口呈现多疲劳源特征,疲劳裂纹扩展区中观察到了大量的撕裂棱、韧窝、以及犁沟。
The low-cycle fatigue properties and cyclic deformation behavior of Cu-Cr-Zr alloys were studied by means of low cycle fatigue( LCF) tests at room temperature. The microstructure and fatigue fracture of the alloy were analyzed by electron backscattered diffraction( EBSD),transmission electron microscopy( TEM),and scanning electron microscopy( SEM). The results show that the relationship between the elastic strain amplitude,the plastic strain amplitude and the number of cycles can be expressed by Basquin and Coffin-Manson formulas,respectively. The cyclic hardening occurs at the later stage of fatigue deformation with a high applied total strain amplitude( Δε_t/2 = 0. 6%),the cyclic deformation microstructure is a mixed structure of dislocation walls,dislocation clusters,and cellular substructure,and the formation of twins is observed. In addition,the fatigue fracture characteristics of the selected material at an applied total strain amplitude of 0. 4% exhibit multiple fatigue sources,a large number of tearing edges,dimples,and furrows are observed in the fatigue crack propagation area.
作者
揭晓
钟强强
王俊峰
陈金水
肖翔鹏
Jie Xiao;Zhong Qiangqiang;Wang Junfeng;Chen Jinshui;Xiao Xiangpeng(School of Mechanical and Electrical Engineering,Taizhou Vocational College of Science and Technology,Taizhou Zhejiang 318020,China;Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou Jiangxi 341000,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2020年第4期105-109,共5页
Heat Treatment of Metals
基金
国家自然科学基金(51561008)。
