Investigation of the microstructure and friction mechanism of novel CoCrCu.sub.0.2FeMo.sub.x high-entropy alloy coating using plasma arc cladding

• Published in: Journal of materials science 2022-11, Vol.57 (42), p.19972
• Main Authors: Xia, Jiayi, Xin, Dongqun, Chen, Xizhang, Xin, Heyang
• Format: Article
• Language: English
• Subjects: Alloys; Hardness; Investigations; Specialty metals industry; Steel, Stainless; Technology application
• ISSN: 0022-2461
• DOI: 10.1007/s10853-022-07792-7

To explore the effect of the Mo element on the microstructure and frictional properties of the coating, we prepared novel CoCrCu.sub.0.2FeMo.sub.x (ie., x values in molar ratio, where x = 0.1, 0.2, 0.3) high-entropy alloy coatings on the surface of 304 stainless steel substrate by using plasma arc cladding technology in this work. By using scanning electron microscope, X-ray diffractometer, microhardness tester and three-dimensional laser measurement microscope, we analyzed the effect of Mo element on the phase structure, microscopic morphology, microhardness and friction properties of the coatings. The friction mechanism of the coatings was carefully investigated. The experimental results show that the CoCrCu.sub.0.2FeMo.sub.x high-entropy alloy coatings are composed of Face-Centered Cubic phase (FCC phase) and [delta] phase (rich Mo, Cr). The microscopic morphology of the alloy changes gradually from branch crystal to eutectic structure with the increase of Mo content. At the same time, the hardness of the coatings increased, while the wear volume, wear rate and average surface roughness decreased. When the Mo content is increased to 0.3, the delamination of the oxide layer is effectively reduced. The friction mechanism changed from abrasive wear, oxidation wear and fatigue spalling to abrasive wear.