文献类型：期刊文献

英文题名：Effects of post-processing and loading orientation on high-cycle fatigue of selective laser melted Ti-6Al-4V

作者：Dong, Nai-Jian[1];Wang, Kang-Kang[1];Wen, Jian-Feng[1];Chen, Bo[2];Tu, Shan-Tung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[2]Univ Leicester, Sch Engn, Leicester LE1 7RH, England

年份：2024

卷号：187

外文期刊名：INTERNATIONAL JOURNAL OF FATIGUE

收录：;EI(收录号：20242416249467);WOS:【SCI-EXPANDED(收录号:WOS:001252958000001)】；

基金：Financial supports from National Natural Science Foundation of China (52122506) , Shanghai Gaofeng Project for University Academic Program Development and the Program of Oriental Scholars of Shanghai Universities are gratefully acknowledged. Bo Chen acknowledges UK's Engineering and Physical Sciences Research Council, EPSRC, for financial support through the First Grant Scheme EP/P025978/1 and Early Career Fellowship Scheme EP/R043973/1. Sean -Anthony Smith and David Wimpenny from the Manufacturing Technology Centre (MTC) , UK, are acknowledged for their support during the sample additive manufacturing, under the Project 12787 -Structural Integrity Trial by AM for Coventry University, UK, as part of the support for the EP/P025978/1. In addition, Nai-jian Dong would like to thank Hua-Yan Hu from Shanghai Jiao Tong University, China, for experimental guidance and discussions and Research Center of Analysis and Test of ECUST, China, for performing the SEM (Hitachi S-3400) characterization.

语种：英文

外文关键词：High cycle fatigue; Life prediction; Microstructure; Additive manufacturing; Titanium alloy

摘要：Recent research on selective laser melted (SLM) Ti-6Al-4V showed that fatigue fracture differs depending on the post-processing and loading orientation. To better understand their influences, tensile and fatigue tests on samples with three post-processing conditions, namely, stress relief (SR), Sub-transus and hot-isostatic-pressing (HIP), were conducted in both the vertical and horizontal loading orientations. The elongation-to-failure of horizontal specimens are consistently higher than the vertical ones for the SR and Sub-transus state, but the opposite trend is observed for the HIP state. This discrepancy is owing to the reduced defect in combination with the {1120} alpha preferred orientation. Comparison of the SR and Sub-transus states suggests that coarser alpha-lath contributes to a longer initiation phase of microcrack from the defect, which improves overall fatigue performance. Fatigue strength of the HIP state is significantly higher than the other two states, exhibiting little anisotropy, and the fatigue-cracking source shifts from the defect to the microstructural facet. Subsequently, a model is proposed to evaluate the high-cycle fatigue of SLM-built Ti-6Al-4V, by incorporating yield strength and elongation-to-failure as additional variables, achieving the life prediction error band within two to five times with respect to the experimental data.