Investigation of thermal residual stresses during laser ablation of tantalum carbide coated graphite substrates using micro-Raman spectroscopy and COMSOL multiphysics
| Autor: | D.V.N. Harish, K. N. Subramanya, B. Anand, A. Bharatish, H. N. Narasimha Murthy |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Multiphysics 02 engineering and technology 01 natural sciences law.invention symbols.namesake chemistry.chemical_compound Residual stress law 0103 physical sciences Materials Chemistry Composite material Thermal spraying 010302 applied physics Laser ablation Process Chemistry and Technology 021001 nanoscience & nanotechnology Laser Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry Ceramics and Composites symbols Deformation (engineering) 0210 nano-technology Raman spectroscopy Tantalum carbide |
| Zdroj: | Ceramics International. 47:3498-3513 |
| ISSN: | 0272-8842 |
| Popis: | Laser ablation of high-temperature ceramic coatings results in thermal residual stresses due to which the coatings fail by cracking and debonding. Hence, the measurement of such residual stresses during laser ablation process holds utmost importance from the view of performance of coatings in extreme conditions. The present research aims at investigating the effect of laser parameters such as laser pulse energy, scanning speed and line spacing on thermal residual stresses induced in tantalum carbide-coated graphite substrates. Residual stresses were measured using micro-Raman spectroscopy and correlated with Raman peak shifts. Transient thermal analysis was performed using COMSOL Multiphysics to model the single ablated track and residual stresses were reported at low, moderate and high pulse energy regimes. The results showed that the initial laser conditions caused higher tensile residual stresses. Moderate pulse energy regime comprised higher compressive residual stresses due to off centre overlapping of the laser pulses. Higher pulse energy (250 μJ), higher scanning speed (1000 mm/s) and moderate line spacing (20 μm) caused accumulation of tensile residual stresses during the final stage of laser ablation. The deviation of experimental residual stresses from COMSOL numerical model was attributed to unaccounted additional stresses induced during thermal spraying process and deformation potentials in the numerical model. |
| Databáze: | OpenAIRE |
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