Effect of WC Particles on the Structure Evolution and Properties of WC-10Co-4Cr Coating deposited by Plasma Spraying

Abstract:

In order to improve the wear resistance of stainless steel surface, WC-10Co-4Cr coating with two grain sizes was prepared by plasma spraying. The phase structure of the coating was characterized by SEM and XRD. Friction and wear test, the influence of grain on the microstructure and friction properties of the coating was studied. The results show that the microstructure of nano-WC-10Co-4Cr coating contains WC and W₂C, and there is also γ phase of Co/Cr(W, C). It is not found that the W2C precipitated in the micron coating will follow the surface of WC particles Epitaxial growth of the coating structure, and nano-agglomerated particles more easily along the flattened particle boundary contraction, significantly reducing the particles within the vertical through cracks. At room temperature and 200℃, nano-WC-10Co-4Cr coating friction coefficient and the average wear rate are better than the micron coating. Compared with the micron coating, nano-WC-10Co-4Cr coating at room temperature wear is rooted in the hard particles induced plow wear, at 200℃ for the wear-resistant micro-domain plowing combined wear mode The And the corrosion potential of 1Cr18Ni9Ti matrix increased from -617mV to -335 ~ -290mV in 3.5% NaCl solution, which decreased the tendency of corrosion.

Key words:plasma spraying; WC-10Co-4Cr; microstructure; microhardness; friction and wear