Microstructure investigation of TiO2 thin layer on 316l steel substrate by sol-gel technique (optimization of parameters via Taguchi method)

Formation of Titania thin layer applied on steel substrate was prepared by dip coating method. Titanium Tetra Iso Propoxide (TTIP) was used as precursor. X-ray difraction (XRD) results showed that TiO2 crystallized in the anatase form. Formation of nano scale layer on the substrates was confirmed by scanning electron microscope (SEM)، transmission electron microscopy (TEM) and atomic force microscopy (AFM). The roughness of thin layer was affected by value of PEG، calcination temperature، number of dipping and pH of sol. In the samples without PEG، increase in number of dipping was led to decrease in roughness، however; different behavior was observed in the samples containing PEG. By increasing the pH value، the coating roughness was decreased.