Thermal relaxation of residual stress in laser shock peened Ti–6Al–4V alloy
| Autor: | Kristina Langer, Zhong Zhou, Sagar Bhamare, Dong Qian, Vijay K. Vasudevan, Youhai Wen, Gokul Ramakrishnan, Seetha R. Mannava |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
business.industry Peening Surfaces and Interfaces General Chemistry Structural engineering Plasticity Condensed Matter Physics Surfaces Coatings and Films Shock (mechanics) Residual stress Thermal Materials Chemistry Stress relaxation Thermal stability Composite material business Softening |
| Zdroj: | Surface and Coatings Technology. 206:4619-4627 |
| ISSN: | 0257-8972 |
| Popis: | Laser shock peening (LSP) induced residual stresses in Ti–6Al–4V, and their thermal relaxation due to short-term exposure at elevated temperatures are investigated by an integrated modeling/simulation and experimental approach. A rate and temperature-dependent plasticity model in the form of Johnson–Cook (JC) has been employed to represent the nonlinear constitutive behavior under both LSP and thermal loads. By comparing the simulation results with experimental data, model parameters for Ti–6Al–4V are first calibrated and subsequently applied in analyzing the thermal stability of the residual stress in LSP-treated Ti–6Al–4V. The analysis shows that the magnitude of stress relaxation increases with the increase of applied temperature due to material softening. Most of stress relaxation occurs before 10 min to 20 min exposure in this study, and stress distribution becomes more uniform after thermal exposure. An analytical model based on the Zener–Wert–Avrami formula is then developed based on the simulation results. The activation enthalpy of the relaxation process for laser shock peened Ti–6Al–4V is determined to be in the range of 0.71 eV to 1.37 eV. |
| Databáze: | OpenAIRE |
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