Mechanical(compressive)form of driving force triggers the phase transformation from βto ω&α"phases in metastable β phase-field Ti-5553 alloy

• 作者: Tayyeb Ali Lin Wang Xingwang Cheng Huanwu Cheng Ying Yang Anjin Liu Xuefeng Xu Zhe Zhou Zixuan Ning Ziqi Xu Xinhua Min
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2021,（19）
• 页码范围: 238-246
• 页数: 9页
• 语种: 英文

摘要

Most of the structural alloys'applications are under static,dynamic,and cyclic forms of loading.Ti-5553 alloy in the beta phase field is being investigated to confirm the mechanism of deformation and phase transformation upon quasi-static and dynamic compression.The Ti-5553 alloy was heat-treated at 900 C(almost 50℃above beta transus temperature)for one hour of soaking time followed by air quenching to achieve a fully β phase field.After that,Dynamic compression(DC)by Split Hopkinson Pressure Bar(SHPB)and Quasi-static compression(QSC)were performed at a strain rate of～103/s and 10-3/s,respectively.Recovered specimens were thoroughly examined by using different tools,such as an Optical microscope(OM),Scanning electron microscope(SEM),High-resolution transmission electron microscope(HRTEM),and Electron backscatter diffraction(EBSD)to get the reliable data for justification of logical conclusions.It is found that the dominating mode of deformation was dislocation slip along with twinning({332}〈113〉)to some extent in both of QSC and DC,but sliding&spalling of the grain boundary is observed more in the former.Stress-induced phase transformation,i.e.,β to α"and 3 toω,took place in the grains saturated with dislocation slips,where the former transformation occurred simultaneously with{332}〈113〉twinning,while β to ω transformation was completed when a set of two adjacent(110)β planes covered±1/6th of the total separation distance between two(next to each other)(111)β planes,by equal but opposite shear in(111)β direction,and it caused 3％shrinkage of two closed packed(110)β planes after transformation.