Effect of Strain Ratio on Fatigue Model of Ultra-fine Grained Pure Titanium

作     者：QIANG Meng YANG Xirong LIU Xiaoyan LUO Lei QIANG Meng;YANG Xirong;LIU Xiaoyan;LUO Lei

作者机构：Wuhan Institute of Marine Electric PropulsionWuhan 430064China 

出 版 物：《Journal of Wuhan University of Technology(Materials Science)》 (武汉理工大学学报（材料科学英文版）)

年 卷 期：2023年第38卷第5期

页      面：1169-1178页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Funded by National Natural Science Foundation of China(No.51474170) the Key Laboratory Project of Shaanxi Provincial Department of Education(No.20js075) 

主　　题：ultra-fine grained pure titanium low cycle fatigue life model mean stress relaxation mode strain ratio fracture morphology 

摘      要：The ultra-fine grained(UFG)pure titanium was prepared by equal channel angular pressing(ECAP)and rotary swaging(RS).The strain controlled low cycle fatigue(LCF)test was carried out at room *** fatigue life prediction model and mean stress relaxation model under asymmetrical stress load were *** results show that the strain ratio has a significant effect on the low cycle fatigue performance of the UFG pure titanium,and the traditional Manson-coffin model can not accurately predict the fatigue life under asymmetric stress ***,the SWT mean stress correction model and three-parameter power curve model are proposed,and the test results are *** final research shows that the threeparameter power surface model has better *** studying the mean stress relaxation phenomenon under the condition of R≠-1,it is revealed that the stress ratio and the strain amplitude are the factors that significantly afiect the mean stress relaxation rate,and the mean stress relaxation model with the two variables is calculated to describe the mean stress relaxation phenomenon of the UFG pure titanium under different strain *** fracture morphology of the samples was observed by SEM,and it was concluded that the final fracture zone of the fatigue fracture of the UFG pure titanium was a mixture of ductile fracture and quasi cleavage *** toughness of the material increases with the increase of strain ratio at the same strain amplitude.