Comparative study of the friction and wear behavior of plasma sprayed conventional and nanostructured WC–12%Co coatings on stainless steel

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 431; no. 1; pp. 290 - 297
• Main Authors: Zhao, Xiao-Qin, Zhou, Hui-Di, Chen, Jian-Min
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2006; Elsevier
• Subjects: Applied sciences; Contact of materials. Friction. Wear; Elevated temperature; Exact sciences and technology; Friction and wear behavior; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metallic coatings; Metals. Metallurgy; Microstructure; Plasma spraying; Production techniques; Surface treatment; WC–Co coating; Friction and wear behavior; Elevated temperature; Plasma spraying; Microstructure; WC–Co coating; Scanning electron microscopy; Sliding wear; Surface coating; Surface morphology; Nanostructure; Hardness; Dispersive spectrometry; X ray diffraction; WC-Co coating; Friction; Composite coating; Stainless steel; Cemented carbides; Wear resistance
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2006.06.009

Conventional and nanostructured WC–12%Co coatings were deposited on 1Cr18Ni9Ti stainless steel substrate using air plasma spraying. The hardness of the coatings was measured, while their friction and wear behavior sliding against Si 3N 4 at room temperature and elevated temperatures up to 400 °C was comparatively studied. The microstructures and worn surface morphologies of the coatings were comparatively analyzed as well by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXA). It was found that the as-sprayed WC–12%Co coatings were composed of WC as the major phase and W 2C, WC 1− x , and W 3Co 3C as the minor phases. The plasma sprayed nanostructured WC–12%Co coating had much higher hardness and refined microstructures than the conventional WC–12%Co coating. This largely accounted for the better wear resistance of the nanostructured WC–12%Co coating than the conventional coating. Besides, the two types of WC–12%Co coatings showed minor differences in friction coefficients, though the nanostructured WC–12%Co coating roughly had slightly smaller friction coefficient than the conventional coating under the same sliding condition. Moreover, both the conventional and nanostructured WC–12%Co coatings recorded gradually increased wear rate with increasing temperature, and the nanostructured coating was less sensitive to the temperature rise in terms of the wear resistance. The worn surfaces of the conventional WC–12%Co coating at different sliding conditions showed more severe adhesion, microfracture, and peeling as compared to the nanostructured WC–12%Co coating, which well conformed to the corresponding wear resistance of the two types of coatings. The nanostructured WC–12%Co coating with a wear rate as small as 1.01 × 10 −7 mm 3/Nm at 400 °C could be promising candidate coating for the surface-modification of some sliding components subject to harsh working conditions involving elevated temperature and corrosive medium.