Formation of Coatings Containing Cr2AlC MAX Phase During Plasma Spraying of Mixture of Cr3C2+Al Powders

In this article, the structure formation and phase composition of coatings containing Cr2AlC MAX phase under the conditions of plasma spraying were studied. Mechanical mixtures of commercially available Cr3C2 and Al powders were used as a material for spraying. The amount of aluminium in the mixtures was 9 and 18 wt.%. As a result of studying physicochemical processes occurring during plasma spraying of mechanical mixtures of selected compositions, the formation of coatings containing Cr2AlC MAX phase was established, the synthesis of which occurs both at the stage of the particles flight of initial components in the plasma jet as a result of the collision and coagulation, and at the stage of a coating layer formation as a result of layering particles deformed during the collision–splats. It is shown that for the formation of a denser coating with a higher MAX phase content for spraying, it is rational to use a mixture of chromium carbide powders with 9 wt.% of aluminium. A coating with the composition 91Cr3C2-9Al (wt.%) has high corrosion resistance in operation conditions in a chloride-acetate solution, and by its indicators of corrosion resistance, is not inferior to the Cr3C2-NiCr coating, which is widely used in industry to protect parts from corrosion and wear. The obtained results show the possibility and feasibility of using mechanical mixtures of commercially available powders for the formation of coatings containing Cr2AlC MAX phase instead of expensive synthesized MAX-Cr2AlC powders.