TiC coatings on stainless steel, Inconel and Mo: Fabrication and testing

Abstract

TiC coating were produced by chemical vapour deposition (CVD) and plasma spray techniques on AISI 316, 310, 304, Inconel 600, and Mo. The 10–30 μm thick coatings formed by CVD at 1323 K show a stoichiometric composition, high density, and preferential orientation (200). Coatings made by plasma spraying also have a stoichiometric composition but traces of titanium oxides and nitrides have been observed. The testing of the coatings involved thermal shock and sputtering at different temperatures. Thermal shock tests were performed by electron beam heating in a 10 −5 Torr vacuum system with a heat load of 1 kW/cm 2 for 1–4 s. In no case disintegration, blistering, or local spall of the coating was observed, even where the substrate was melted during the heat pulse. However, owing to differential thermal expansion, cracks were observed in the case of CVD coatings. Cracks were not evident in plasma spray coatings. Sputtering at medium temperature is in agreement with that previously measured at room temperature.