Research on the Microstructure and Mechanical Properties of Electrodeposited Nicocr-Based Alloy Coatings

Abstract

304 stainless steel is commonly used in the manufacture of thermal power unit components, inferior hardness and abrasion resistance limits the 304 stainless steel further wide application. Preparation of NiCoCr-based alloy coatings on the surface of 304 stainless steel could improve mechanical properties. The NiCoCr-based alloy coatings were prepared on the 304 stainless steel by electrodeposition. The microstructure, phase composition, hardness, and tribological properties of the three groups of coatings were studied. The results showed that the three groups of coatings had a dense structure without cracks, and the elements were uniformly distributed in the coatings. The three groups of coatings formed a single-phase face-centered cubic (FCC) disordered solid solution structure, in which the NiCoCr and NiCoCrFe medium entropy alloy (MEAs) coatings were amorphous, and the NiCoCrFeMn high entropy alloy (HEAs) coatings were a mixture of crystalline and amorphous structures. The hardness and tribological properties of the three groups of coatings were significantly improved compared with the matrix. The improvement of the mechanical properties of the NiCoCrFeMn high entropy alloy coatings is mainly attributed to the solid solution strengthening and fine-grain strengthening mechanism. This study provides theoretical and technical support for the electrodeposition of HEAs in aqueous solutions, which broadens the application prospects of HEAs in surface protection.

Keywords: Electrodeposition, High-entropy alloy coatings, Microstructure, Strengthening mechanism