Microstructure evolution and erosion behaviour of thermally sprayed AlCoCrNiMo0.1 high entropy alloy coating

Novel AlCoCrNiMox (x = 0.1 wt%) non-equiatomic high entropy alloy (HEA) powders were synthesized by mechanical alloying. A single solid-solution was formed. X-Ray Diffraction (XRD) analysis of milled powders reveals a BCC phase after 20 h of milling. Field emission scanning electron microscopy (FESEM) with EDAX mapping confirmed the formation of a homogenous mixture. The milled alloy was coated onto a 316 steel substrate using High-velocity Oxy-fuel (HVOF) coating. The slurry erosion resistance exhibited by the coating was tested using Water-jet Erosion tester with 24 m/s to 30 m/s jet velocity at 30 degrees, 45 degrees, 60 degrees, and 90 degrees angular impingement. Spallation due to adhesion with subsequent layered lamellae fracture was observed to occur during erosion.