文献类型：期刊文献

英文题名：Elucidating the effect of gradient structure on strengthening mechanisms and fatigue behavior of pure titanium

作者：Li, Xiao[1];Sun, Bin-Han[2];Guan, Bo[3];Jia, Yun-Fei[1];Gong, Cong-Yang[1];Zhang, Xian-Cheng[1];Tu, Shan-Tung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Minist Educ, Key Lab Pressure Syst & Safety, Shanghai 200237, Peoples R China;[2]Max Planck Inst Eisenforschung GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany;[3]Chongqing Univ, Sch Mat Sci & Engn, Chongqing 400044, Peoples R China

年份：2021

卷号：146

外文期刊名：INTERNATIONAL JOURNAL OF FATIGUE

收录：;EI(收录号：20210509842116);WOS:【SCI-EXPANDED(收录号:WOS:000623083900003)】；

基金：This work was sponsored by National Key Research and Development Program of China (2018YFC1902404), National Natural Science Foundation of China (51725503 and 51975211) and 111 Project, Shanghai Rising-Star Program (20QA1402500) and Innovation Program of Shanghai Municipal Education Commission (2019-01-07-00-02E00068).

语种：英文

外文关键词：Gradient nanostructure; Pure titanium; Microstructural evolution; Strengthening mechanism; High-cycle fatigue

摘要：Gradient nanostructured (GNS) layer was fabricated on the pure titanium using ultrasonic surface rolling process. With the coaction of deformation twinning, phase transformation, and dislocation slip, a spatial gradient of grain size distribution was formed. Nanocrystalline and amorphous phase exist simultaneously on the top surface. The effect of grain refinement, dislocation density, and deformation twinning on strength was analyzed quantitatively. Stress-controlled fatigue tests showed that enhanced fatigue strength was achieved on the GNS Ti due to the synergetic effect of microstructure and unique mechanical properties. The primary mechanism was fatigue induced grain coarsening sustained the cumulative plastic strain during cyclic deformation and the GNS layer could change the crack initiation mode.