Improving wear and corrosion properties of alumina coating on AA7075 aluminum by plasma electrolytic oxidation: Effects of graphite absorption

An alumina coating with a thickness of 20–50 μm was deposited by plasma electrolytic oxidation (PEO) on an AA 7075 Al alloy in an alkali-aluminate electrolyte using a 5 kW DC power supply. After the formation of the coating, the effects of current density, electrolyte concentration, and process time on the coating characteristics were investigated comprehensively. In order to achieve improved tribological and corrosion properties, the prepared...