K. Y. Sastry, M. Lubrick, V. Leshchynsky, R. G. Maev, University of Windsor, Windsor, ON, Canada
This paper describes the influence of post-spray heat treatment parameters on mechanical properties of Ni-TiC composite coatings. Thin Ni-TiC composite coatings were produced by cold gas dynamic process (also referred as cold spray or kinetic spray process) on an Inconel alloy substrate. In the coating process, mechanically mixed micron-sized Ni-TiC powders (~50mm) were injected into a de-Laval nozzle propelled by a supersonic gas stream to high velocity (>300 m/s) to impinge upon a substrate. The coatings are formed subsequently as the metallic particles are severely deformed plastically and bonded to both the substrate and to one another. However the adhesion strength levels were determined to be in the range of 30-40MPa. A subsequent post-spray heat treatment in vacuum was found to enhance the bond strength of the coated particles with the substrate due to good metallurgical bonding caused by diffusion mechanism.
Summary: Thin coatings were formed on substrates using low pressure radial injection gas dynamic spray method. Some of the samples were subjected to post-spray heat treatment to remove inter-particle micro-porosity, homogenize and consolidate the buildup via an atom diffusion mechanism. Both structure and properties of un treated and heat treated samples were studied and compared.
