커뮤니티

연구성과

MRL [MRL] Prof. Chong Soo Lee:Enhancing low-cycle fatigue life of commercially-pure Ti by deformation at…

페이지 정보

profile_image

작성자 최고관리자

댓글 0건 조회 515회 작성일 2021-11-11 13:28

본문

In this study, the low-cycle fatigue behavior of a cryogenic-rolled commercially pure titanium alloy was investigated, and compared with those of undeformed and room-temperature rolled ones. The amounts of deformation twins increased to >69.8% after cryogenic temperature rolling, and to 27.5% after room temperature rolling. Strain-controlled low-cycle fatigue tests were performed at total strain amplitudes 0.4

%Δεt2 1.2%. The Coffin-Manson and hysteresis energy-based models confirmed that low-cycle fatigue resistance was remarkably improved with increasing the volume fraction of deformation twins by pre-deformation. As the proportion of deformation twins in the microstructure increased, the hysteresis loop area decreased, the striation spacing decreased, and the severity of crack-deflection behavior increased. At low Δεt2

 = 0.4%, dislocation recovery was suppressed in the pre-deformed microstructure, so cyclic behavior was stable. However, at Δεt/2 ≥ 0.8%, the recovery became the predominant mechanism, so well-defined cell structures formed and cyclic softening occurred. The smaller dislocation cells formed in RTR and CTR were considered to cause more severe crack arrest than in AR. 

댓글목록

등록된 댓글이 없습니다.