Influence of the Fuel and High-Velocity Spray Technique on Corrosion and Antifouling Properties of Cu Coating

Metallic surfaces exposed to natural or marine water are susceptible to the adhesion of living microorganisms, a process called biofouling. Different thermal spraying processes, especially the high kinetic energy ones, can be used to face the challenges of distinct types of material wear. This work deposited pure Cu coatings using different variations of high-velocity oxy-fuel (HVOF): propane, kerosene, and ethanol fuel, and compared to 304SS and Cu deposited by high-pressure cold spray (CS). The samples were characterized by OM, SEM, XRD. Corrosion properties were measured during electrochemical tests in NaCl solution. Biofouling test conducted with Pseudomonas aeruginosa pathogen was cultured to prepare the challenge suspension and then applied on each replicate for 21 days in a Time-Kill assay. The HVOF-propane splats were less deformed than HVOF-ethanol ones, and the HVOF-kerosene promoted the highest microhardness among the samples due to its higher oxide content. The HVOF-propane coating has the lowest count in the biofilm formation test, followed by the HVOF-ethanol. All HVOF Cu coatings had a better antifouling performance than the 304SS reference.