Influence of deposition voltage on the tribological properties of WS2-reinforced microarc oxidation composite coatings on 7075 aluminum alloy

To address the limitations of high friction coefficient and porous structures inherent in conventional microarc oxidation (MAO) coatings, a MAO-WS2 composite coating was fabricated on 7075 aluminum alloy by combining MAO with electrophoretic deposition. The influence of processing parameters was investigated, with the deposition voltage optimized at 40 V. The results demonstrate that this optimal composite coating exhibits superior electrochemical and tribological performance. Quantitatively, the self-corrosion current density of the 40 V sample reached 3.66 × 10−9 A/cm2, representing a reduction of three orders of magnitude compared to the 7075 substrate. Furthermore, compared to the pure MAO coating, the composite coating achieved a 63.5% reduction in the wear rate and a decrease in the friction coefficient by approximately 0.5. Investigation into the wear mechanism revealed that the WS2 particles effectively sealed the micropores and promoted the formation of a stable tribo-transfer film, thereby simultaneously enhancing corrosion resistance and wear resistance. These findings confirm that the MAO-WS2 composite strategy provides a highly effective pathway for enhancing the longevity and reliability of aluminum alloys in complex tribo-corrosive environments.