Title

The effect of spraying temperature on the corrosion and wear behavior of HVOF thermal sprayed WC-Co coatings

Document Type

Journal Article

Publication Title

Ceramics International

Publisher

Elsevier Ltd

School

School of Engineering

RAS ID

29594

Comments

Originally published as: Azizpour, M. J., & Tolouei-Rad, M. (2019). The effect of spraying temperature on the corrosion and wear behavior of HVOF thermal sprayed WC-Co coatings. Ceramics International, 45(11), 13934-13941. Original publication available here

Abstract

Cobalt matrix carbides are favorite cases of wear and corrosion-resistant coatings. Among thermal spray processes the high-velocity oxy-fuel (HVOF) spraying is a popular choice because of its unique properties. In this paper the effect of particles’ temperature on the porosity, corrosion as well as wear behavior of high-velocity oxy-fuel (HVOF) thermally sprayed WC-12Co coating has been studied. The temperature of particles was measured using a Spray-Watch diagnostic system. Also the scanning electron microscopy (SEM), image analysis, and X-ray diffraction (XRD) were used for examining the powder and the coating. The corrosion potential and corrosion current density was evaluated using potentio-dynamic polarization test. Results show that the porosity is affected by thermal flow on the coating surface. Besides, a higher particle temperature resulted in achieving more amorphous phases and eventually the higher corrosion resistance. Sample A was coated with an impact temperature of 2012.4 °C. Although the porosity was higher than other sprayed samples (1.7%), the higher content of amorphous phase led to recording a higher corrosion resistance (64.3E-6A). Sample B was coated with an impact temperature of 1880 °C for which the Jcorr was 67.2E-6 A. Sample C was sprayed with a low impact temperature of 1702 °C for which a surface porosity of 1% and the low corrosion resistance of 79.5E-6A were recorded. Based on the experiments it was concluded that for the WC-12Co coating the corrosion resistant phases have the dominant influences on the corrosion resistance.

DOI

10.1016/j.ceramint.2019.04.091

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