Effect of silane hybrid modification on the distribution of etched tunnels in aluminum foils

In this paper, aluminum foils were modified using silane solutions incorporating corrosion-inhibiting ions to regulate electrochemical direct-current (DC) etching behavior. Electrochemical measurements and scanning electron microscopy (SEM) were employed to investigate the effects of silane modification concentration, temperature, and immersion duration on the corrosion inhibition performance of silane-modified films. Based on the optimized silane modification conditions, the influence of hybrid modification with silane combined separately with cerium salt (Ce 3+ ) or molybdate (MoO 4 2- ) on etched tunnel distribution was further examined. The results demonstrate that the corrosion inhibition effect of silane modification exhibits a positive correlation with both concentration and temperature, whereas the dependence on immersion duration follows a bell-shaped trend with an intermediate optimum. Silane modification with individually introduced Ce 3+ or MoO 4 2- enhances corrosion inhibition efficacy and improves the uniformity and dimensional consistency of etched tunnels. When the inhibitor concentration exceeds the optimal level, Ce 3+ incorporation leads to ion agglomeration and reduced protective performance, while excessive MoO 4 2- induces strong surface passivation and a pronounced decrease in tunnel density.