Influence of Ni-coated carbon fiber on tribological and corrosion behavior of the NiCrAl-Bentonite self-lubricating composite coating

To address the problem that a high-content lubricating phase can decrease the hardness and wear resistance, resulting in the spallation of the coating during the friction process. In this study, spherical composite powders of NiCrAl-Bentonite, NiCrAl-Bentonite doped with 3 wt% carbon fiber (NiCrAl-3CF), and NiCrAl-Bentonite doped with 3 wt% nickel-coated carbon fiber (NiCrAl-3NCF) were fabricated using ball milling and spray granulation. Subsequently, these composite powders were utilized to prepare corresponding coatings on SUS321 substrates. The hardness and wear test indicated that the doping of carbon fiber (Cf) and nickel-coated carbon fiber (Ni@Cf) increased the hardness and diminished the abrasive wear and damage to the grinding ball during the wear test, thereby reducing the Coefficient of Friction (COF). The electrochemical test indicated that the connection and bridging effects of Cf and Ni@Cf within the coating changed the corrosion direction and prolonged the corrosion path, thereby improving the corrosion resistance. This study clarifies the mechanism of Cf and Ni@Cf on tribological performance and corrosion resistance of the coating, it holds considerable reference value for their application in thermal spraying lubricating coating.