Thermal Spraying of Ti2AlC coatings

Abstract

Compound Ti2AlC is a MAX phase discovered in the early 1960s. It is well known that Ti2AlC has excellent physical and mechanical properties and chemical stability [1]. On the surface of Ti2AlC, at high temperatures, a stable, protective oxide layer, Al2O3, is usually formed [2], whose coefficient of thermal expansion is approximately equal to the coefficient of thermal expansion of Ti2AlC [3]. If this Al2O3 layer is compact, it stops further oxygen penetration and protects Ti2AlC from further oxidation. Due to its excellent oxidation resistance, MAX phase Ti2AlC has great potential in producing protective coatings for components in the industry that are exposed to high temperatures [4,5]. Coating Ti2AlC can be applied to the substrate by different thermal spraying processes. Cold spraying (CS), high velocity air fuel (HVAF), and high velocity oxygen fuel (HVOF) processes can be singled out as particularly interesting due to the possibility of applying thicker coatings to the substrate [6]. This paper describes the technology of applying the Ti2AlC phase on heat-resistant steel using the HVOF system of the third generation, which uses a mixture of oxygen and kerosene as fuel. Also, the filler material, which was in the form of powder, and the microstructure of the obtained coating were characterized by scanning electron microscopy (SEM). The Ti2AlC coating was successfully applied and a relatively good mechanical bond was achieved with the substrate. The goal of surfacing the Ti2AlC coating was a potential application for protecting steel from oxidation at elevated temperatures.

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