Interface structure, mechanics and corrosion resistance of nano-ceramic composite coated steels

Ceramic coating is an effective means to suppress steel corrosion, while the interface performance is far from being understood. Herein, the effects of component doping on the interface structure, multi-scale mechanical properties and corrosion resistance of alumina-based ceramic-coated steels were studied by means of density functional theory (DFT) and experimental characterizations. The DFT results show that electron transfer issues occur significantly between Fe and O atoms at the Fe/Al2O3 interface. The larger valences of Fe and O are promoted by the doping of Ti, Zr, and Ce atoms, and improve the interfacial electrostatic interaction, spacing, and energy. It screens out the well mix proportions, that is, taking titanium doped alumina as the matrix, doped with Zr or Ce. Experiments confirm that incorporation of ZrO2 or CeO2 additives effectively improve the microstructure of the ceramic-coated steel, significantly enhancing both interface bonding and corrosion resistance. In addition, the element diffusion occurs at the interface between nano-ceramic coating and steel, forming an interfacial mutual pinning structure.