Friction and Wear Properties of Silicon Nitride-Based Composites with Different hBN Content Sliding against Polyether-Etherketone at Different Speeds under Artificial Seawater Lubrication

In the present study, the friction and wear behaviors of Si₃ N₄-hBN(Hexagonal boron nitride) ceramic composites against polyether-etherketone in artificial seawater were investigated, and the sliding speed was varied from 0.52 to 1.73 m/s to study the effect. It was found that the friction coefficients and wear rates decreased with the increase in sliding speed for Si₃ N₄-hBN (with the hBN content ranging from 5% to 20%) against PEEK(Polyether-ether-ketone); the sliding pairs represented an upward trend as the speed increased for Si₃ N₄-hBN (with an hBN content of 0 and 30%) against PEEK. This result was mainly attributed to complex friction resistance sources, such as mechanical meshing and the shear strength of soft tribofilm. On the other hand, both the hBN content and sliding speed had a significant effect on the tribological performance of the Si₃ N₄-hBN/PEEK pairs. Meanwhile, the lowest friction coefficient of 0.07 and wear rates below 10⁻⁶ mm³ /Nm were obtained from the Si₃ N₄-20%hBN/PEEK pair at the speed of 1.73 m/s.