| About this Abstract |
| Meeting |
13th International Conference on the Technology of Plasticity (ICTP 2021)
|
| Symposium
|
13th International Conference on the Technology of Plasticity (ICTP 2021)
|
| Presentation Title |
The Influence of Temperature and Strain Rate on the Superplastic Deformation Behavior and Microstructure Evolution of TNW700 Alloy |
| Author(s) |
Lixia Ma, Min Wan, Weidong Li, Jie Shao, Xuepiao Bai |
| On-Site Speaker (Planned) |
Lixia Ma |
| Abstract Scope |
TNW700 titanium, as a near-α high temperature titanium alloy, is designed to work at 700°C for a short term service. Superplastic deformation behaviour of TNW700 alloy was investigated in a temperature range of 900-975°C and a strain rate range of 0.0005-0.01s -1 to identify the optimum deformation temperature and strain rate. The microstructure evolution after high temperature tensile was investigated using scanning electron microscope. The research found that TNW700 alloy has an excellent superplasticity. The elongation exceeds 200% at various deformation conditions except 975°C with higher strain rate of 0.005 and 0.01s-1, and the maximum elongation of 613% was obtained at temperature of 925°C and strain rate of 0.001s-1. The flow stress is sensitive to temperature and strain rate, and it increases with decreasing temperature and increasing strain rate. In addition, the flow stress exhibits strongly work hardening with increasing of true strain, and the instantaneous work hardening exponent <i>n and the critical hardening strain is accelerated as the strain rate decreases. The strain rate sensitivity exponent (m) is higher than 0.4 when the temperature is lower than 975°C, which corresponds to dynamic recrystallization and grain boundary sliding. The m is 0.229 at temperature of 975°C, corresponding to dynamic grains growth mechanism. The deformed microstructure of TNW700 alloy consists of β grains and equiaxed α grains. Increasing the temperature is beneficial to the transformation of α phase into the β phase, which resulted in an increase in the volume fraction of the β phase. The β grains growth rapidly at higher temperatures and lower strain rates due to higher diffusion coefficient. |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |