Synergistic effect of ultrasonic cavitation erosion and corrosion of WC–CoCr and FeCrSiBMn coatings prepared by HVOF spraying

• WC–10Co–4Cr and FeCrSiBMn coatings were prepared by HVOF spraying process.
• Synergistic effect of cavitation erosion and corrosion of the coatings was studied.
• Contribution of corrosion component to total volume loss rate was different.
• Mechanical effect was the main factor for cavitation erosion–corrosion behavior.

The high-velocity oxygen-fuel (HVOF) spraying process was used to fabricate conventional WC–10Co–4Cr coatings and FeCrSiBMn amorphous/nanocrystalline coatings. The synergistic effect of cavitation erosion and corrosion of both coatings was investigated. The results showed that the WC–10Co–4Cr coating had better cavitation erosion–corrosion resistance than the FeCrSiBMn coating in 3.5 wt.% NaCl solution. After eroded for 30 h, the volume loss rate of the WC–10Co–4Cr coating was about 2/5 that of the FeCrSiBMn coating. In the total cumulative volume loss rate under cavitation erosion–corrosion condition, the pure cavitation erosion played a key role for both coatings, and the total contribution of pure corrosion and erosion-induced corrosion of the WC–10Co–4Cr coating was larger than that of the FeCrSiBMn coating. Mechanical effect was the main factor for cavitation erosion–corrosion behavior of both coatings.