Tribological behavior of plasma electrolytic oxidation coatings on the surface of Mg–8Li–1Al alloy

Plasma electrolytic oxidation coatings were fabricated on the surface of Mg–8Li–1Al. The tribological behavior of the coated and uncoated Mg–Li alloy was investigated under dry friction conditions against a Si3N4 ball as counter-face material. The results indicated that the tribological behavior is greatly affected by the microstructure and phase compositions of the coatings. The PEO coatings significantly improved the properties of friction and wear of Mg–Li alloy.

► The PEO coating A was composed of MgO, Mg2SiO4 and ZrO2.
► The PEO coating B was composed of MgO, ZrO2 and TiO2.
► The wear mechanism of coating A is abrasive wear through the micropolishing action.
► The better anti-friction property of coating B is due to the existence of TiO2.
► The PEO coating improves the friction and wear resistance of Mg–8Li–1Al alloy.