Tribological Performance of Shaft and Surface Pairs with PPS and its Composites in Seawater under Cyclic Loading

Shaft-surface friction pairs in marine equipment endure considerable wear and corrosion in seawater, particularly under cyclic loading. A friction and wear test bench was employed to replicate the conditions faced by ship stern shafts and bearings in seawater. The study aimed to assess the tribological performance of three types of polyphenylene sulfide (PPS) materials: pure PPS, PPS reinforced with 30% glass fiber (30% GF in PPS matrix), and PPS reinforced with 30% carbon fiber (30% CF in PPS matrix), against 316L stainless steel under varied lubrication conditions. Results demonstrate that all PPS variants exhibit minimal friction force and wear loss in seawater, with 30% CF in the PPS matrix displaying the least friction and wear characteristics. Friction force fluctuates within a 2.5 ~ 5 N range, and wear loss is 0.027 g. However, due to the uneven bonding of glass fiber (GF) within the PPS matrix, the addition of GF did not significantly enhance the materials’ anti-friction properties and wear resistance. The predominant wear mechanism involves severe three-body abrasive wear caused by GF detachment from the friction pairs surface. Additionally, the study explores carbon fiber’s resilience to cyclic loading, the lubricating effect of seawater mixed with carbon fiber debris, and the transfer mechanism of polymer films. These findings highlight synergistic anti-friction and wear-resisting effects between carbon fiber, seawater, and polymer transfer films, offering valuable insights for selecting effective shaft friction pairs materials in challenging seawater conditions.