Surface Modification of 316L Stainless Steel with Al/TiO₂-Doped Organosilicone Coatings

The surfaces of 316 L stainless steel,a construction material,were modified with the coatings,deposited by spraying of organosilicone resin mixed with Al/TiO₂ nanoparticels and cured in air.The influence of the polyurethane (PU) to polyethyl silicone (SM) ratio on the curing behavior and oxidation resistance at 600℃ was investigated with X-ray diffraction,energy dispersive spectroscopy,scanning electron microscopy and infrared spectroscopy.The results show that the PU/SM ratio has a major impact.Specifically,as the PU/SM increased from 20 wt% to an optimal of 30 wt%,partial solidification of SM resin changed into complete solidification for 24 h and the reticular framework formed because of dehydration and condensation of silicon hydroxyl groups.As the oxidation time increased,the surface-roughness,interfacial-adhesion and oxidation-resistance increased,possibly because the formation of Al₂O_3,originated from a continuous oxidation of Al-powder,prevented O₂-diffusion,enhanced oxidation-resistance and reinforced the interfacial adhesion.