Fabrication of CrFeCoNiSi High Entropy Alloys Dispersed with Silicon Compounds by Low-Pressure Plasma Spraying

We aimed to fabricate CrFeCoNiSi HEA deposits dispersed with Si compounds by low-pressure plasma spraying, and we evaluated the structure and properties of the alloy deposits. A heat treatment was applied to the fabricated alloy deposits, and the formation process of precipitates in HEAs was investigated. We fabricated HEA deposits without segregation on substrates with and without water-cooling. The fcc solid solution existed in the as-sprayed deposits and heat-treated deposits. Si compounds were dispersed in the deposits. The precipitates became coarser as the heat-treatment temperature increased. The 873 K heat-treated deposits had the highest hardness both with and without water-cooling. Nanoscale precipitates were formed inside the crystal grains in the as-sprayed deposits with water-cooling. The 1273 K heat-treated deposits satisfied the definition of HEAs.