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Transformation-Induced Creep and Creep Recovery of Shape Memory Alloy.
Kohei Takeda1, Hisaaki Tobushi2, Elzbieta A Pieczyska3
1Department of Mechanical Engineering, Aichi Institute of Technology, 1247 Yachigusa, Yakusa-cho, Toyota 470-0392, Japan. q11801qq@aitech.ac.jp.
Materials (Basel, Switzerland)
|August 18, 2017
Summary
Shape memory alloys exhibit creep and creep recovery under stress-controlled conditions due to martensitic transformations. Understanding these thermomechanical properties is crucial for designing reliable shape memory alloy components.
Area of Science:
- Materials Science
- Mechanical Engineering
- Thermodynamics
Background:
- Shape memory alloys (SMAs) undergo martensitic transformations influencing their deformation behavior.
- Creep and creep recovery in SMAs are critical factors in the design of components subjected to constant stress.
- Understanding the kinetics of martensitic transformation is key to predicting SMA behavior.
Purpose of the Study:
- To investigate the phenomenon of transformation-induced creep and creep recovery in shape memory alloys.
- To analyze the conditions governing martensitic transformation kinetics under stress.
- To experimentally characterize the thermomechanical properties of TiNi shape memory alloy.
Main Methods:
- Experimental investigation of TiNi shape memory alloy under stress-controlled conditions.
- Analysis of martensitic transformation kinetics.
- Monitoring temperature changes during loading and unloading cycles.
Main Results:
- Creep deformation occurs when stress is held constant during the martensitic transformation stage.
- Creep recovery is observed when stress is held constant during the reverse transformation stage.
- The volume fraction of the martensitic phase correlates directly with creep strain.
Conclusions:
- Martensitic transformation kinetics dictate creep and creep recovery in SMAs under specific stress conditions.
- TiNi shape memory alloy exhibits significant transformation-induced creep and recovery.
- These findings are vital for the accurate design and application of SMA elements.
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