|About this Abstract
||MS&T22: Materials Science & Technology
||Processing-Microstructure-Property Relationships of Titanium and Titanium Alloys
||Enhancing Low-cycle Fatigue Life of Commercially-pure Ti By Deformation At Cryogenic Temperature
||Geonhyeong Kim, Seyed Amir Arsalan Shams, Jae Nam Kim, Jong Woo Won, Seong Woo Choi, Jae Keun Hong, Chong Soo Lee
|On-Site Speaker (Planned)
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 variants. The amounts of deformation twins increased to over 70% after cryogenic temperature rolling, and to 27% after room temperature rolling. Strain-controlled low-cycle fatigue tests were performed at various total strain amplitudes from 0.4% to 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, and the severity of crack-deflection behavior increased. At total strain amplitude of 0.4%, dislocation recovery was inhibited in the pre-deformed microstructure, so cyclic behavior was stable. However, at total strain amplitude from 0.8% to 1.2%, the recovery actively occurred, so well-defined cell structures formed and cyclic softening became dominant behavior.