Bending Creep and Stress Relaxation of Ti3AlC2 at High Temperature
Creep and stress relaxation of Ti3AlC2 were investigated using three-point bending tests at 800-1200°C under various load levels. The results show that the creep rate significantly increases with increasing temperature in the rang of 1000-1200°C. Subcritical crack growth during the creep process was found to be the main failure mechanism, i.e., the stress intensity factor increases with the creep-induced crack growth and results in the ultimate fracture. The lower limit of stress relaxation was considered as the threshold value of zero-creep stresses, and the ratio of the threshold stress to the applied stress was defined to be a parameter of creep resistance for estimating deformation behavior at high temperature. SEM examination confirmed that the creep failure in Ti3AlC2 was governed by such a damage evolution: cavitation ® crack initiation ® crack extension ® fracture.
Wei Pan, Jianghong Gong, Chang-Chun Ge and Jing-Feng Li
Y. W. Bao and Y. C. Zhou, "Bending Creep and Stress Relaxation of Ti3AlC2 at High Temperature", Key Engineering Materials, Vols. 280-283, pp. 1373-1378, 2005