Thermal stability of eutectic FeNiCoCrTi0.6Nb0.4 high-entropy alloy coating

The eutectic FeNiCoCrTi0.6Nb0.4 high-entropy alloy coating (HEAC) is annealed in Argon at 450°C, 850°C and 1050°C to investigate the thermal stability. The results show that annealed coatings are all composed of BCC solid solution and Laves phase with no production of new phases. The fine eutectic cells can be maintained at a higher temperature in that continuous intracellular coarsening does not occur until annealing at 1050°C. With the increase of annealing temperature, the microhardness and wear resistance of FeNiCoCrTi0.6Nb0.4 coating increase first and then decrease slightly. Especially, the microhardness of FeNiCoCrTi0.6Nb0.4 annealed at 1050°C is only 6.03% lower than that of unannealed one, and the wear rate is only 10.70% higher than that of unannealed one, which strongly indicates that eutectic FeNiCoCrTi0.6Nb0.4 HEAC has excellent thermal stability and can be well applied in high-temperature environments.