Effects of surface texturing on the tribological behaviors of PEO/PTFE coating on aluminum alloy for heavy-load and long-performance applications

This paper reports on the fabrication and tribological performances of surface textured plasma electrolytic oxidized (PEO) coatings containing polytetrafluoroethylene (PTFE) on aluminum alloy (PEO/PTFE). The ordered arrays of circular dimples were created on PEO ceramic coating surface by laser surface texturing and vacuum penetration of nanosized-PTFE was followed in vacuum chamber. The tribological properties of PEO/PTFE and textured PEO/PTFE coatings were evaluated at load of 5–25 N using a UMT-4 tribometer under dry condition. The results shown that surface texturing can effectively reduce the friction coefficient of contact interface for 72,000 cycles at 5 N and greatly improve the bearing capacity of PEO/PTFE coating, because of the constantly compensation of lubricating PTFE film in the wear track. This study established a new approach to fabricate self-lubricating ceramic PEO coating on aluminum alloys.