Geometric Influence of Hard Phase on Corrosion Performance between WC-Reinforced Coatings Prepared by High-Velocity Oxygen-Fuel Spray and Electric Contact Strengthening

Abstract

Several kinds of WC-reinforced coatings were prepared by high-velocity oxygen-fuel spray (HVOF) and electric contact strengthening (ECS), respectively, and their corrosion behaviors in 3.5% NaCl solution were investigated. The microstructure, element distribution, phase and corrosion resistance of these coatings were compared. The results showed that, compared with HVOF-sprayed coatings, the ECS-prepared coatings were denser and with lower porosity. Simultaneously, the ECS coatings that used raw powder commercial WC-12Co retained the original spherical geometry of the hard phase. In open-circuit potential measurements, these ECS coatings gave higher stable potentials (Eocp). In potentiodynamic polarization tests, although the corrosion currents (icorr) of the homogeneous coatings were approximately the same, these ECS coatings still exhibited higher corrosion potentials (Ecorr). The spherical geometric distribution of the hard phase led to a bounded diffusion model caused by the diffusion change of corrosion products.

Effect of Pulsed-Plasma Treatment on the Structural-Phase Composition and Tribological Properties of Detonation Coatings Based on Ti–Si–C

“…The detonation coatings have been widely used [1][2][3][4] to increase the wear resistance and corrosion resistance of machine parts, as well as to improve their physical and mechanical properties. At the same time, coatings based on the MAX phase have been widely studied due to their unique properties, such as the resistance to oxidation, the ease of processing, relatively low cost of materials, the excellent thermal stability and wear resistance of materials [5].…”