Preparation of an Anodized Shot-Peened Layer on Steel and Its Controllable Wettability

In this work, we have presented a detailed study on the effect of shot peening on anodization of medium carbon steel. Anodization has been conducted on both non-shot-peened and shot-peened steel. The results show that shot peening procedure facilitates the subsequent anodization significantly. The mechanism for promoting anodization by shot peening has been discussed. After anodization, the shot-peened steel forms an amorphous α-Fe2O3 film with a geometric pattern. More importantly, the α-Fe2O3 film and the shot-peened layer constitute an anodized shot-peened layer, which exhibits a multi-scale structure. Due to this multi-scale structure, the anodized shot-peened layer shows a controllable wettability. It can be used as a hydrophilic or a hydrophobic coating.