中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 12 No. 4 August 2002 |
evolution of ULTIMET superalloy:
experiment and theoretical modeling
（1. Department of Materials Science and Engineering, University of Tennessee,
Knoxville, TN 37996, USA;
2. Metals and Ceramics Division, Oak Ridge National Laboratory,
Oak Ridge, TN 37831, USA;
3. Haynes International Inc., Kokomo, IN 46904, USA）
Abstract:High-speed, high-resolution infrared thermography, as a non-contact, full-field, and nondestructive technique, was used to study the temperature variations of a cobalt-based ULTIMET alloy subjected to cyclic fatigue. During each fatigue cycle, the temperature oscillations, which were due to the thermal-elastic-plastic effects, were observed and related to stress—strain analyses. The change of temperature during fatigue was utilized to reveal the accumulation of fatigue damage. A constitutive model was developed for predicting the thermal and mechanical responses of ULTIMET alloy subjected to cyclic deformation. The model was constructed in light of internal-state variables, which were developed to characterize the inelastic strain of the material during cyclic loading. The predicted stress —strain and temperature responses were found to be in good agreement with the experimental results.
Key words: fatigue; thermography; temperature; constitutive model; NDE; superalloy
