Effects of WC on the Microstructure, Wear and Corrosion Resistance of Laser-Deposited CoCrFeNi High Entropy Alloy Coatings

Abstract

Wear and corrosion resistant properties of high entropy alloy coatings (HEAC) on H13 steel are of particular interest for industrial applications. The CoCrFeNi HEA/WC composite coatings (HEACC) developed in this study were successfully prepared by incorporating 10–40 wt.% WC into a matrix of CoCrFeNi HEA using laser cladding on an H13 steel substrate. Phase transformation, microstructure evolution, microhardness, wear and corrosion resistance of CoCrFeNi HEACC were investigated. According to the results, all CoCrFeNi HEACC exhibited higher wear and corrosion resistance than the H13 steel substrate. Wear resistance of CoCrFeNi HEACC first increases and then decreases with an increase in the concentration of WC particles, and the lowest coefficient of friction and the shallowest depth of wear groove were observed after adding 30 wt.%. Grain refinement strengthening and second-phase particle strengthening may contribute to enhanced hardness and wear resistance of coatings with WC additions. In addition, all the CoCrFeNi HEACC exhibited improved corrosion resistance. In particular, an addition of 10 wt.% WC helped to significantly improve the corrosion resistance and ease of passivation of CoCrFeNi HEACC.

A Study of the Microstructure and Mechanical and Electrochemical Properties of CoCrFeNi High-Entropy Alloys Additive-Manufactured Using Laser Metal Deposition

“…After the AM process, all of presented only FCC phases, independent of laser power. Thus, the LMD meth to produce an in situ alloy with the desirable FCC HEA microstructure from metal powders [28,29]. During the laser deposition process, residual stress was after the rapid melting and cooling of the deposition layers, changing the lattic Thus, the migration and intensity of the main peaks were affected [32].…”

“…[21] studied the microstructural evolution of untreated LMD Al 0.3 CoCrFeNiNb 0.5 HEA with the highest average hardness of 715 HV0.5. The microstructure and mechanical properties of LMD-prepared CoCrFeNi HEAs with the addition of Si [22], Mn [23][24][25][26][27], WC [28], and Al [29] were also studied to improve its micro-mechanical properties [30] or comprehensive performance [31]. Additionally, the LMD process itself has also been seen to affect the mechanical properties of bulk materials.…”

Microstructures, Corrosion Resistance and Wear Resistance of High-Entropy Alloys Coatings with Various Compositions Prepared by Laser Cladding: A Review

“…These elements usually have strong slagging and deoxidation abilities, which is conducive to improving the wear resistance and processability of the coating. Bingqian Wu et al [36] studied the effect of Si content on the microstructure and wear resistance of FeCoCr 0.5 NbSi 0.4 HEA coatings; the results showed that with the increase of Si content, the microstructure of the coating changed obviously, the M 2 B phase decreased, the eutectic structure also disappeared gradually, and the wear resistance of the coating at FeCoCr 0.5 NbSi 0.4 was the best. During wear, the phases with low hardness values are fatigued off by the cyclic action of the WC balls, while the phases with higher hardness are not worn off, which shows that the wear mechanism of the FeCoCr 0.5 NiBSi 0.4 high-entropy alloy coating is mainly fatigue wear.…”

Iso-material manufacturing of 304 stainless steel: Microstructure, corrosion-cavitation erosion synergistic behaviour

“…Apparently, the materials used in marine parts are supposed to obtain a combination of desirable properties such as high strength and ductility, high resistance to wear, corrosion and CE, while this combination is difficult to co-exist in a single bulk material, and even it does, manufacturing costs might be high. Fortunately, surface modification techniques [14][15][16][17] provide an effective way to solve the above problems through tailoring the surface properties while retaining the bulk properties. During the past decades, the development of surface modification against the wear, high-temperature oxidation and CE primarily relied on the protective coating with extensively expensive elements.…”