Dip coating of a carbon steel sheet with Ni reinforced TiO sub(2) nanoparticles

In this work carbon steel plates were dip-coated with a composite film obtained from a colloidal suspension of Ni-TiO sub(2). Suspensions with different solids contents were used to evaluate the adherence of the film and the microstructural features. The samples were characterized using both optical and scanning electron microscopy, energy dispersive spectroscopy and microhardness. The microstructural analysis revealed that the films have high porosity at the surface. However, an interfacial region was observed demonstrating that there was good adhesion between both materials. This region shows an increased hardness that can be attributed to diffusion mechanism of nickel from the composite film to the steel matrix. Besides the interface, there was an abnormal grain growth, followed by a region of smaller grains of austenite and at longer distances near the center of the plate some colonies of pearlite appear.