Cyclic deformation behaviors of Ti-46Al-2Cr-2Nb-0.15B alloy during thermo-mechanical fatigue tests

• Published in: Transactions of Nonferrous Metals Society of China Vol. 20; no. 11; pp. 2174 - 2180
• Main Author: 项宏福 戴安伦 王冀恒 李惠 杨锐
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2010; Provincial Key Laboratory of Advanced Welding Technology,Jiangsu University of Science and Technology, Zhenjiang 212003, China%Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
• Subjects: Asymmetry; cyclic stress response; Deformation; dislocation; Dislocations; Fatigue tests; Hardening; hysteresis loop; Hysteresis loops; Softening; Strain; Stress-strain relationships; thermo-mechanical fatigue; TiAl基合金; Titanium base alloys; titanium-aluminium alloy; 不对称性; 变形行为; 变循环; 温度范围; 热机械疲劳; 疲劳试验; 透射电镜观察; dislocation; titanium-aluminium alloy; thermo-mechanical fatigue; hysteresis loop; cyclic stress response
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(09)60438-6

Thermo-mechanical fatigue tests were carried out on the gamma-TiAl alloy in the temperature range of 500-800℃ under mechanical strain control m order to evaluate its cyclic deformation behaviors at elevated temperature. Cyclic deformation curves, stress-strain hysteresis loops under different temperature--strain cycles were analyzed and dislocation configurations were also observed by TEM. The mechanisms of cyclic hardening or softening during thermo-mechanical fatigue （TMF） tests were also discussed. Results showed that thermo-mechanical fatigue lives largely depended on the applied mechanical strain amplitudes, applied types of strain and temperature. On the hysteresis loops appeared two apparent asymmetries： one was zero asymmetry and the other was tensile and compressive asymmetry. Dislocations configuration and slip behaviors were contributed to cyclic hardening or cyclic softening.