Development and characterization of sol–gel silica–alumina composite coatings on AISI 316L for implant applications
By Tiwari, S.K.; Mishra, T.; Gunjan, M.K.; Bhattacharyya, A.S.; Singh, T.B. & Singh, R.
Published in Surface and Coatings Technology
2007
Abstract
Sol–gel alumina coatings were deposited on medical grade stainless steel (AISI 316L) with an intermediate layer of silica by dip-coating method. The coatings obtained were homogeneous, crack-free and consisted of low crystalline γ-Al2O3 along with some boehmite phase. EDAX revealed the presence of only Al in the film. The corrosion performance of alumina-coated stainless steel was evaluated by electrochemical polarization, open-circuit potential measurement and chronoamperometry in Ringer's solution. Coating has shown to enhance the pitting potential of AISI 316L by ∼ 470 mV and reduced passive current ≤ 10- 9 A cm- 2. The formation of thermodynamically stable silica–alumina interface was proposed to account for enhanced corrosion protection behaviour of the coating.