Understanding deformation and fracture mechanism of Ti-55531 alloy under complex loading conditions:a case of pre-tensioned torsion  

作　　者：Kong-Liang Hu Chao-Wen Huang Hong-Tao Zeng Jiang Yang Dan Liu Tian-Xin Li Ming-Pan Wan Yong-Qing Zhao 

机构地区：[1]National and Local Joint Engineering Laboratory for High-Performance Metal Structure Materials and Advanced Manufacturing Technology,Guizhou University,Guiyang,550025,China [2]Key Lab of Materials Structure and Strength of Guizhou Province,Guizhou University,Guiyang,550025,China [3]College of Mechanical and Equipment Engineering,Hebei University of Engineering,Handan,056038,China [4]School of Materials and Energy Engineering,Guizhou Institute of Technology,Guiyang,550003,China [5]Northwest Institute for Nonferrous Metal Research,Xi’an,710016,China

出　　处：《Rare Metals》2024年第12期6673-6693,共21页稀有金属(英文版)

基　　金：financially supported by the National Natural Science Foundation of China (Nos.52061005 and 52261025);the Science and Technology Program of Guizhou Province (Nos.YQK[2023]009 and [2023]278)。

摘　　要：The deformation and fracture failure of aerospace structural components are primarily affected by complex loading conditions.This study aims to investigate how various pre-tension strains(0%,4%and 6%)influence the torsional properties,deformation and fracture mechanism of the Ti-5Al-5Mo-5V-3Cr-1Zr(Ti-55531)alloy with the bimodal microstructure.The results indicate that increasing the pre-tension strain gradually decreases the torsional strength of specimens.However,their torsional ductility initially increases(from 0 to 4%pre-tension strain)and then decreases(from 4 to 6%pre-tension strain).This can be attributed to the significant influence of different pre-tension strains on the deformation mechanism of each phase in the alloy.Under pure torsion loading,the primary α(α_(p))phase mainly undergoes the{0002}basal slip for deformation.However,at a pre-tension strain of4%,the torsional deformation mechanism of α_(p)transforms into crossing reaction between the{1010}prismatic slips.As the pre-tension strain further increases to 6%,{1011}pyramidal slips were further activated.Moreover,with an increase in pre-tension strain,there is a significant rise multiple slips probability within the α_(p) during torsional deformation.On contrary,for the secondaryα(α_(s))phase,the probability of{1011}_(α)twins formation during torsional deformation firstly rises and then reduces.These findings indicate thatαphase,particularly α_(p),plays a crucial role in accommodating deformation.This discovery offers valuable insights for further adjustments and optimizations of material microstructure and properties.Additionally,modifying external load can alter the stress state of components and enhance their fracture resistance during service,thereby broadening their range of applications and improving material reliability.

关 键 词：Metastableβtitanium alloy Pre-tension strain Tension and torsion composite loads Deformation behavior Fracture mechanism 

分 类 号：TG1[金属学及工艺—金属学]