D. Kosikowaski, P. S. Mohanty, A. Hart, University of Michigan, Dearborn, MI

Summary: Coatings with combined erosion and oxidation resistance are critical to many industrial systems. This paper presents a cost effective technique to produce functionally gradient erosion/oxidation resistant coating. A hybrid HVOF-Arc spray gun has been employed to deposit these coatings. The stainless steel matrix material utilized here is in the form of wires that are melted by arcing process. A high velocity combustion jet carrying the tungsten/chrome carbide particles atomizes the molten material and mixes the cermet particles with the matrix material. The feed rate of the matrix material and the reinforcing material are controlled independently giving a continuous variation of reinforcement phase. The in-flight particle characteristics of these materials have been characterized. The resulting microstructure and the erosion/oxidation properties are presented.