A comparative study of thermal shock tests : chemical composition and micro-structural analyses on the surface of TiN coatings after thermal shock by laser ablation

摘要

The chemical composition and microstructural analyses on the surface of TiN coatings which were deposited onto SUS 304 substrates by an arc ion plating technique were investigated after heat-treatment using laser ablation. For a comparative study, as-deposited TiN specimens were heated at various temperatures for 30 minutes in a furnace. After the laser ablation, the surface of the TiN coatings exhibited cracks and spalling at the center of the ablated region and there was no noticeable phase variation including an increase of oxidized phases which were shown by the furnace heating process. The variation of binding energy peaks for the elements of TiN coatings showed that the laser thermal shock method reduced the effects of oxidation and impurities. The laser thermal shock method, consequently, could be subjected locally to thermo-mechanical stresses and enable a reduction of the side effects for a thermal shock test.