Properties of Cold Sprayed and Controlled Atmospheric Plasma Sprayed High Entropy Alloy (CoCrFeMnNi) Coatings

High entropy alloys such as the Cantor Alloy (CoCrFeMnNi) have gained significant interest over the last decade for their unique microstructure and mechanical/chemical properties. Advanced processing of High entropy alloys has led to new engineering problems, specifically in application of coatings that retain phase and reduce oxidation. To reduce these effects during processing, this study explored two thermal spray techniques with the CoCrFeMnNi alloy: Controlled Atmosphere Plasma Spray and Cold Spray. Both techniques resulted in no measurable oxygen uptake in the coating or phase precipitation. Selective depletion of Manganese was observed in the plasma spray process at splat interfaces and is thought to be due to the high vapor pressure of Mn compared to the other elements in the alloy. Cold Spray of the material resulted in no alterations in composition or phase from the feedstock but did result in a doubling of Vickers hardness due to work hardening.