Characterization and Wear Behavior of CoCrNi Medium Entropy Alloy Coating on Al Alloy by Resistance Seam Processing

Abstract

In this study, the CoCrNi medium entropy alloy (MEA) coating was firstly fabricated on 5083Al alloy by the resistance seam processing (RESP) method. After processing, the CoCrNi MEA powders were transformed into a simple face-centered cubic (FCC) structural coating with an average thickness of 381 ± 4 µm, and the heat-affected zone was rarely found in the Al alloy matrix. Furthermore, a certain amount of Al element penetrated into gaps of coating and Co, Cr and Ni elements were homogeneously distributed. The average hardness of the coating was 775 ± 68 HV_0.2, which was higher than the similar MEAs prepared by other reported methods. To evaluate its wear properties, the wear behaviors of CoCrNi MEA coating and 5083Al alloy were studied in detail. Although the main wear mechanisms of both materials were adhesive wear, the high hardness and plastic deformation ability of the MEA coating effectively improved its wear performance. Practically, the average wear rate was ∼10 times lower than 5083Al alloy. The RESP method was proved to be an effective method for preparing the high wear-resistance MEA coating on Al alloy.