Effect of Submicron SiC Particles on the Properties of Alcocrfeni High Entropy Alloy Coatings.

The high entropy alloy (HEA) coatings are potential candidates for advanced application in the protection of steel and other traditional alloys due to their excellent physical and mechanical performance. The AlCoCrFeNi alloy series were favorably studied due to comparably low cost and stable performance. In this research, the AlCoCrFeNi coatings were prepared through surface mechanical abrasion treatment (SMAT). The process implied the comprehensive effect of cold welding and friction. The submicron-size SiC particles were added into the raw materials in different amounts. For SMAT, a high-energy ball milling method was adopted to promote the alloying of metals, disperse SiC_p, and combine the powder to the carbon steel substrate. Afterward, the phase composition, microstructure of coatings, and distribution of reinforcement were detected through XRD and SEM analysis, separately, and the effect of SiC particles content on the properties of the coatings was analyzed. The results show that the addition of submicron-sized SiC significantly improved the density and stiffness of the HEA coating and diminished defects and surface roughness. Сoatings containing SiC display enhanced adhesion force and wear resistance. The proposed mechanism is that the submicron SiC particles promoted mechanical alloying of pure metal and intensified the adherence and cold welding of the coating. Especially, herein, the addition of 15 wt.% SiC granted the best comprehensive properties of the coating. Excessive SiC content led to the deterioration of coating plasticity and the growth of cracks. [ABSTRACT FROM AUTHOR]