Screening of low friction coefficient tribopairs of different rubber with various steels and ceramics under water lubrication

Water is a transmission medium with broad application prospects. In order to screen some excellent tribopairs under water lubrication, the friction behaviors of NBR, HNBR, and EPDM sliding against 11 kinds of counterpart materials including stainless steels and ceramics were investigated. The friction experiments were carried out under different rotation speeds. SEM images of partial tribopairs were exhibited to discuss the reasons for the differences in their friction behaviors. The results indicate that when sliding against different rubber materials under various rotation speeds, 17-4PH regularly has the lowest friction coefficient and the worn surfaces of corresponding rubber material are flat. In contrast, Cr₂O₃-related materials always have the worst friction performances and the corresponding rubber material surfaces are seriously worn. 17-4PH and 2507 exhibit similar tribological properties, and the tribological properties of the four WC-based materials also resemble highly, which can be inferred from the micro surface morphologies of their corresponding rubber materials. Moreover, the tribological properties of NBR are most affected by the experimental conditions. The tribological performances of HNBR are prior to those of NBR. EPDM has enhanced tribological properties with the increase of rotation speed.