Tribological behavior of polydopamine-modified boron nitride nanoplatelets-reinforced silicate ceramic coatings

Boron nitride nanoplatelets (BNNP) serve as promising reinforcing fillers for enhancing the tribological properties of ceramic coatings. However, the strong van der Waals forces between BNNP layers lead to aggregation and poor dispersion in the coating matrix, limiting their effectiveness. To address this issue, this study introduced polydopamine (PDA)-modified BNNP into silicate ceramic coatings and systematically investigated the effect of PDA-BNNP content on the structural characteristics, surface quality, and tribological behavior of the coatings. Results indicate that PDA effectively introduced hydrophilic groups on the surface of BNNP, improving its dispersibility in coatings. At an optimal PDA-BNNP content of 0.6 wt%, the coefficient of friction was reduced by 19.2 % and 13.2 % under 10N and 15N loads, respectively, while the wear rate decreased by 33 % and 44 %, compared to the unmodified coating. However, further increasing the PDA-BNNP content led to a deterioration in friction performance. This study demonstrates that modifying BNNP with an optimal amount of PDA effectively improves its dispersion and enhances the tribological properties of BNNP-reinforced silicate ceramic coatings. The novel PDA-BNNP hybrid provides a promising solution to the aggregation problem in BNNP-reinforced coatings for enhanced self-lubrication and wear resistance.