Аңдатпа
AlCoCrFeNi2.1 eutectic high entropy alloy (HEA) composite coatings reinforced by Al2O3 particles were prepared by detonation spraying (DS) on low alloy steel substrates. The effect of annealing at different temperatures on the microstructure and mechanical properties of the coatings was further studied. The as-deposited AlCoCrFeNi2.1-30 wt. % Al2O3 composite coating exhibited a dual-phase FCC+BCC lamellar microstructure matrix with Al2O3 reinforcement particles. The crystalline structure and lamellar microstructure of the coatings highly retained after annealing at 500°C and 800°C, however, a partial dissolution of BCC was noted after annealing. Moreover, annealing improved inter-diffusion and annihilated pores, therefore highly compensated the decline in microhardness due to strain relief effect of annealing. The as-deposited composite exhibited a microhardness value of 415 HV, which slightly decreased to about 409 HV and 403 HV after annealing at 500°C and 800°C, respectively. The microhardness values demonstrated low fluctuation over the thickness of the coatings.