Deformation and damage features of a TiAl-Nb alloy during creep
By means of heat treatment, creep properties measurement and microstructure observation, the deformation and damage features of a TiAl-Nb alloy are investigated.Results show that after solution and aging treatment, the microstructure of alloy consists of uniform and regular lamellar γ/α2 phases, the regular boundaries are located in between the lamellar γ/α2 phases.Under the applied stress of 200 MPa at 800 ℃, the creep lifetime of the TiAl-Nb alloy is measured to be 297 h.The deformation mechanism of alloy during creep is dislocations slipping in the lamellar γ/α2 phases, the creep dislocations may be decomposed to form the configuration of the partials plus stacking faults.In the latter stage of creep, the primary / secondary slipping systems of dislocations are alternately activated to contort the lamellar α2/γ phases, which may promote the initiation of cracks on the boundaries parallel to the lamellar γ/α2 phases, and propagated along the boundaries at about 45° angles relative to the stress axis up to the occurrence of creep fracture.
TiAl-Nb alloy Microstructure Creep Cracks Fracture mechanism
Sugui Tian Xiaoxia Lv Huichen Yu Qi Wang Fangfang Sun
School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation,Science and Technology on Ad
国际会议
2015 International Symposium on Structural Integrity(2015年国际结构完整性学术会议)
沈阳
英文
113-117
2015-05-16（万方平台首次上网日期，不代表论文的发表时间）