Thermally sprayed Ti3SiC2 and Ti2AlC MAX-phase coatings

Compounds of the material group of the so-called MAX-phases combine metallic and ceramic properties. For example, they are excellent thermal and electrical conductors and also exhibit high resistance to thermal shock, oxidation and wear. Currently thin MAX-phase coatings are prepared by physical and chemical vapor deposition. Thermal spraying offers the opportunity to prepare thick coatings in an economically efficient way. In this work, MAX-phase coatings were deposited from modified Ti3SiC2 and Ti 2AlC commercial feedstock powders using high velocity oxy-fuel (HVOF) and atmospheric plasma spraying (APS). Feedstock powders and coatings were studied by microscopy and XRD. Despite the low quality of the feedstock powders, well adhering and relatively dense coatings were deposited on the substrates. In result of the decomposition TiC is formed, its amount depending on the spray process. HVOF coatings showed denser microstructures and contained higher amounts of the MAX-phases. Further progress regarding the coating properties can be expected from a significant improvement of the processability of feedstock materials.