Cold-Sprayed FeCoNiCrMn High-Entropy Alloy (HEA) Coating: Microstructure and Tribological Properties

High-entropy alloys are of great interest due to their unique phase structure. They are constructed with five or more principal alloying elements in equimolar or near-equimolar ratios and thus derive their performance from multiple elements rather than one. In this work, solid-state cold spraying is used for the first time to produce a FeCoNiCrMn high-entropy alloy coating. As a low-temperature process, cold spraying completely retained the high-entropy phase structure in the coating without any phase transformation. Examination shows that the grains underwent significant refinement due to dynamic recrystallization and that the coatings are much harder than the feedstock powder because of increased dislocation density and grain boundaries.