Cold-Sprayed Ti-Carbon Nanofibers: Study of Conductive and Electrochemical Properties

The cold gas spray (CS) technique has emerged as a promising coating deposition method in the last decades for many materials, including Ti and most recently metal matrix composites, such as graphene-reinforced Ti. In this study, CS Ti coatings reinforced with two types of carbon nanofibers (GFs), HCNFs and MWCNTs, were evaluated regarding their electrochemical, electrical, and thermal properties before and after heat treatments (HT) at 700 and 1000 °C. The results indicated that incorporating GFs did not alter the CS Ti coatings deposition efficiency, porosity, or hardness in as-sprayed condition. HT reduced the CS Ti and Ti-GFs coatings resistivity by 21 and 23%, respectively, as well as improved their thermal conductivity by 25 and 32%, respectively. CS Ti-GFs coatings demonstrated an impressive reduction in corrosion rate of up to 80% compared to unreinforced Ti. These findings highlight the potential of CS Ti-GFs composite coatings applied through CS for industrial applications requiring high corrosion resistance. However, improvements by incorporating GFs in Ti powder in thermal and electrical properties were limited, indicating the need to optimize matrix–reinforcement interaction and CS process parameters to maximize their performance in these areas.