Inconel 713C Coating by Cold Spray for Surface Enhancement of Inconel 718

Inconel 713C is a nickel-based superalloy usually considered as a material of poor weldability due to its susceptibility to hot cracking in the heat-affected zones. Cold spray, a solid-state deposition technology that does not involve melting, can be proposed as a methodology to deposit Inconel 713C for surface enhancement of other target components. In this study, Inconel 713C coating was deposited on Inconel 718 substrate with a high-pressure cold spray system. The coating was characterized in terms of microstructure, hardness, and wear properties. The cold-sprayed Inconel 713C coating has a low porosity level and refined grain structures. Microhardness of the Inconel 713C coating was much higher than the Inconel 718 substrate. The sliding wear tests showed that the wear resistance of the cold-sprayed Inconel 713C coating is three times higher than the Inconel 718 substrate, making the coating a suitable protective layer. The main wear mechanisms of the coating include oxidation, tribo-film formation, and adhesive wear.

Film Cooling with Surface Enhancements

Film cooling has been studied for many decades but the study of film cooling using surface enhancements is still relatively new. In this project numerical analysis has been carried out to find the film cooling performance of ramp, flow aligned blocker, and trench surface enhancements in comparison to the standard elliptical injection configuration. A comparative study of the effects of the blowing ratio has also been carried out for each surface enhancement configuration. In addition to calculating and discussing the centerline and laterally averaged film cooling effectiveness results, detailed analysis of the flow and temperature field of each configuration is also presented. In the end the laterally averaged film cooling effectiveness results suggested that flow aligned blockers would provide the greatest film cooling improvements with closer hole spacing.