Sol-Gel Coatings on 316L for Surface properties Enhancement

Abstract

Sol-gel alumina was deposited on medical grade stainless steel (SS316L) with and without intermediate layer of silica by dip-coating method. Aluminium isopropoxide and tetraethoxysilane were used as source of Al2O3 and SiO2. The cycles of dipping and drying at 150oC were repeated four times and heated finally at 500oC to get alumina coating on SS316L. The Al2O3 powder obtained by drying the gel at 100oC and heated subsequently at 500oC was charac-terized through FTIR and XRD for purity and phase format-ion. The surface morphology and roughness of the coatings were studied through SEM and AFM. The thickness and the scratch hardness of the film were determined by surface profilometer and scratch tester, repectively. The perfo-rmance of alumina coated stainless steel was evaluated in vitro by classical electrochemical techniques and compared to the uncoated material.