Exploring the implications of CoCrFeNiCu high entropy alloy coatings on tribomechanical, wetting behavior, and interfacial microstructural characterizations in microwave-clad AISI 304 stainless steels
Authors: Sharma Shubham , Dwivedi Shashi Prakash , Pattanaik Ashutosh , Bisht Yashwant Singh , Kalyani Teku , Mann Vikasdeep Singh , Kumar Rajeev , Kumar Abhinav , Kozak Drazan , Lozanovic Jasmina 
Published: February 2025

Abstract
The exploration of high-performance coatings is specifically necessary for enhancing the mechanical, thermal, and corrosion-resistant characteristics of structural steels in response to the demand for cutting-edge materials in engineering applications. The current study addresses an existing void in the development of durable coatings that gain benefits from the distinctive characteristics of CoCrFeNiCu high entropy alloys (HEA) for stainless steel substrates, with a particular emphasis on SS 304. The primary objective was to examine the microstructural, mechanical, and corrosion behaviors of SS 304 that had been coated with CoCrFeNiCu HEA employing a microwave cladding process. HEA particles were prepared through mechanical milling, and a controlled cladding process was conducted under an inert environment. A variety of meticulous investigations, including Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and wear rate measurements, have been performed to thoroughly assess crucial parameters, including surface hardness, resistance to corrosion, and wear behavior. This study explores the influence of a CoCrFeNiCu high entropy alloy (HEA) coating (20 % each component) on SS-304 steel. Utilizing microwave cladding, the coating demonstrated a substantial impact on wetting behavior, interfacial microstructure, hardness, and corrosion resistance. Surface hardness was substantially enhanced by the cladding process, resulting in a 54.76 % rise from 210 HV to 325 HV. This enhancement substantially raised the mechanical strength of the steel. Under 120 h of corrosion testing in 3.5 wt.% NaCl, a minimal weight loss of 0.342 mg was observed, suggesting that the material exhibited substantial corrosion resistance. In addition, the material’s capacity to resist abrasive forces has been demonstrated by the relatively minimal wear rate of 0.0012 mm3/m that was noticed throughout wear resistance experiments. Effective interfacial adhesion, bonding strength, and uniform distribution were observed by the coating, which resulted in enhanced mechanical characteristics and durability in harsh circumstances. Wetting characteristics indicated enhanced hydrophobicity/hydrophilicity compared to the uncoated surface. SEM images displayed a well-adhered, homogeneous interfacial region, signifying a robust metallurgical bond. The cladding surface exhibited a uniform distribution of CoCrFeNiCu HEA particles. Notably, the steel’s surface hardness increased by approximately 54.76 % postdeposition. These findings underscore the potential of CoCrFeNiCu HEA coatings in advancing steel surface properties for improved performance and durability. The potential of CoCrFeNiCu HEA coatings to enhance the performance and longevity of SS 304 steel in chemical, marine environments, etc., applications that necessitate superior resistance to wear, protection against corrosion, and structural or mechanical integrity is underscored by these findings.