| Abstract: |
Cold Gas Dynamic Spraying (CGDS) is a low-temperature, high deposition rate process wherein the coating formation takes place by severe plastic deformation of powder particles impacting a substrate at supersonic velocities attained using a De Laval nozzle. This technique is capable of depositing temperature and/or oxygen sensitive materials efficiently. However, generic CGDS coatings are populated by numerous weak inter-splat boundaries and often large cold worked stresses. Consequently, the properties of the coatings, such as electrical conductivity, modulus of elasticity, corrosion resistance etc. are greatly influenced by the presence of such defects. Prior work carried out in the authors laboratory on CGDS coatings has revealed that a post-deposition heat treatment serves to homogenise the splat structure as well as recover some key properties viz., electrical conductivity for copper and corrosion resistance in the case of zinc and stainless steel coatings. In the present study, a high-energy Infra-red (IR) emitter has been utilized for post-treatment of CGDS coatings. Such an IR emitter offers an economical tool for rapid post-treatment of the coatings and preliminary results have demonstrated that the above technique holds considerable promise for enhancing as-deposited coating properties. Illustrative results based on studies carried out with Cold Sprayed Copper and Zinc will be presented to highlight the efficacy of IR-based post-treatment. The role of IR treatment parameters will be discussed and ensuing results also compared with those obtained using conventional heat treatment procedures.
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