Tribological properties of dopamine-modified dimple textured surfaces filled with PTFE

Abstract

PTFE-filled textured surfaces were impregnated with the dopamine dipping solution to improve their tribological performances. Ball-on-disc wear experiments were conducted to compare tribological properties of three surfaces: the textured surface, filled textured surface and modified filled textured surface. The worn surfaces, wear debris, and shedding areas of the PTFE were measured, and shear strength between the PTFE block and medium carbon steel after impregnation modification was analysed. Experimental results showed that compared with textured surfaces, filled textured surfaces and modified filled textured surfaces had lower friction coefficient values and cross-sectional areas of wear scars. Compared with the filled textured surface, the modified filled textured surface reduces filled gaps by 63.5% and the shedding ratio of the PTFE within dimples by 63.2%. The research results demonstrate that tribological performances of the filled textured surface can improve after impregnation modification. Polydopamine can react to covalent-noncovalent interaction with PTFE and medium carbon steel. Polydopamine acts as a binder to improve the bonding strength between the PTFE and the inner wall of dimples. Polydopamine can reduce the shedding ratio of the PTFE and maintain the antifriction function of the PTFE in dimples.