Enhancement mechanism exploration of hexagonal boron nitride on the mechanical and tribological properties of polytetrafluoroethylene composites by experiments and molecular dynamics simulation

This study investigates the influence of hexagonal boron nitride (h-BN) content on the mechanical and tribological properties of polytetrafluoroethylene (PTFE)/glass fibers/MoS2/h-BN 2 /h-BN composite materials. Their tensile strength and hardness were measured to evaluate the improvement effect of h-BN. The results indicate that h-BN particles can enhance the tensile strength and surface hardness of the PTFE composites. Tribological properties were conducted under dry conditions using a ball-on-disk tribometer, and the worn surfaces were examined through scanning electron microscopy. The results reveal that the friction coefficient initially decreases and then increases with the increase of h-BN content. The lowest friction coefficient (reduced from 0.118 to 0.088) and wear rate (reduced by 16.16% compared to the sample without h-BN addition) is achieved with the addition of 0.05 wt% h-BN. Additionally, Energy Dispersive Spectroscopy (EDS) analysis was conducted on the SiC balls to reveal the wear mechanism by analyzing the composition of the transfer film. Finally, molecular dynamics simulations revealed the movement and interactions of h-BN and PTFE at different content. This study provides valuable guidance for the incorporation of h-BN particles into PTFE composites.