In situ preparation of MAO/TiO2 composite coating on WE43 alloy for anti-corrosion protection

Microarc oxidation (MAO) coatings have attracted a lot of researchers because of their excellent adhesion to the substrate alloys. However, the porous structure of the MAO coating allows aggressive ions to invade the MAO/ substrate interface and deteriorates the anti-corrosion of the coating. Herein, to seal the micropores and improve corrosion protection, a dense and biocompatible TiO2 layer was successfully developed on the MAO coating of the biodegradable WE43 alloy. Characteristics of the composite coating were analyzed, and then the degradation behavior of the samples was investigated. Results demonstrated that the micro-defects in MAO coating were effectively sealed by TiO2. Compared with WE43 alloy, the corrosion current density of the sample coated with MAO/TiO2 was reduced by three orders of magnitude, indicating that the composite coating has an excellent anti-corrosion behavior. In addition, the anti-corrosion mechanism of MAO/TiO2 composite coating was also suggested.

Automated summary

The research successfully developed a method to add a TiO2 layer on the MAO coating of WE43 alloy, effectively improving the anti-corrosion performance of the coating, reducing the corrosion current density, and proposing the anti-corrosion mechanism of the composite coating.