Synergistic mechanism for the tribocorrosion of 6005A aluminum alloy in 3.5 wt.% NaCl solution

Purpose Increasing efforts have been made to study the corrosion and wear of aluminum alloy, yet there is little information on the influence of the corrosion, especially pitting corrosion, on wear and synergism with each other. This study aims to explore the tribocorrosiom mechanism of 6005A alloy in 3.5 wt.% NaCl solution. Design/methodology/approach Tribocorrosion of 6005A aluminum alloy has been conducted in 3.5 Wt.% NaCl solution under open-circuit potential, potentiodynamic and potentiostatic conditions. After the tribocorrosion experiments, the wear tracks and their cross sections, prepared by cutting transverse to the sliding direction, were examined with the aid of scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy. Wear cross-sectional profiles were quantified using laser confocal microscopes. The Vickers microhardness measurements were performed inside and outside of the wear track by a digital microhardness tester. Findings The results demonstrate that the applied load has significant influence on the negative shift of corrosion potential from −1.0 VSEC at 0.5 N to −1.3 VSCE at 10 N and the corresponding wear volume from 0.005 mm3 at 0.5 N to 0.48 mm3 at 10 N. The polarization curves under sliding reveal that wear promotes anodic dissolution and suppresses pit growth. The dependences of tribocorrosion on applied potential have been researched, and it follows that the wear volume increases with increasing applied potential from 0.13 mm3 at −1.5 VSCE to 0.25 mm3 at −0.7 VSCE, where the material loss is mainly controlled by pure mechanical wear and synergistic effect. Meanwhile, the component of corrosion-accelerated wear in the synergism plays an important role in tribocorrosion because of the pitting corrosion within the wear track. Originality/value This work found the critical factor in tribocorrosion and gave a new idea for material selection or further reinforcement technology for aluminum alloys.