Titania/hydroxyapatite bi-layer coating on Ti metal by electrophoretic deposition: Characterization and corrosion studies

Abstract Titania–hydroxyapatite (HAp) bi-layer coating on Ti metal substrate with improved adhesion strength is fabricated by a simple two step processes: electrodeposition of Ti sol and electrophoretic deposition of HAp powder, followed by heat treatment at 800 °C. At optimized process parameters, the bi-layer developed consists of dense, thin and crystalline titania interlayer with porous, thick and crystalline HAp top layer. The heat treatment of bi-layer coating allows elemental intermixing at the interface of TiO 2 and HAp, as determined by energy dispersive X-ray spectroscopy (EDX) and Raman spectra analysis. Compared to monolithic HAp coating, the TiO 2 /HAp bi-layer coating shows significant enhancement in the adhesion strength (48 MPa) as well as corrosion resistance without compromising its biocompatibility. The steep increase in adhesion strength is believed to be due to mechanical interlocking and diffusion bonding at the interface. Presence of dense titania interlayer in the bi-layer coating reduces the corrosion current in Ringer's solution to a negligible value (∼100 nA).

[1]  M. Grätzel,et al.  Surface Modification of Titanium with Phosphonic Acid To Improve Bone Bonding: Characterization by XPS and ToF-SIMS , 2002 .

[2]  T. Mosmann.  Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. , 1983, Journal of immunological methods.

[3]  M. Fathi,et al.  Novel hydroxyapatite/tantalum surface coating for metallic dental implant , 2007 .

[4]  K. Wong,et al.  Adhesion study of pulsed laser deposited hydroxyapatite coating on laser surface nitrided titanium , 2009 .

[5]  Zhenjun Wu,et al.  Fabrication and characterization of hydroxyapatite/Al 2O 3 biocomposite coating on titanium , 2006 .

[6]  G. S. Wu,et al.  Fabrication and optical properties of TiO2 nanowire arrays made by sol–gel electrophoresis deposition into anodic alumina membranes , 2003 .

[7]  A. Conde,et al.  Sol–gel coatings for protection and bioactivation of metals used in orthopaedic devices , 2004 .

[8]  M. Jelínek,et al.  Pulsed Laser Deposition of Thin Films , 1997 .

[9]  M. McKee,et al.  Chemical modification of titanium surfaces for covalent attachment of biological molecules. , 1998, Journal of biomedical materials research.

[10]  Yu-peng Lu,et al.  Plasma-sprayed hydroxyapatite+titania composite bond coat for hydroxyapatite coating on titanium substrate. , 2004, Biomaterials.

[11]  Hyoun‐Ee Kim,et al.  Hydroxyapatite coating on titanium substrate with titania buffer layer processed by sol-gel method. , 2004, Biomaterials.

[12]  J. Jiménez,et al.  Influence of the sandblasting on the subsurface microstructure of 316LVM stainless steel: Implications on the magnetic and mechanical properties , 2009 .

[13]  S. Altıntaş,et al.  Hydroxyapatite coating on titanium substrate by electrophoretic deposition method: Effects of titanium dioxide inner layer on adhesion strength and hydroxyapatite decomposition , 2008 .

[14]  Manoj Komath,et al.  Pulsed laser deposition of hydroxyapatite on titanium substrate with titania interlayer , 2011, Journal of materials science. Materials in medicine.

[15]  R Z LeGeros,et al.  Biodegradation and bioresorption of calcium phosphate ceramics. , 1993, Clinical materials.

[16]  Yung‐Chin Yang,et al.  Bonding Strength Investigation of Plasma-sprayed HA Coatings on Alumina Substrate with Porcelain Intermediate Layer , 2006, International Thermal Spray Conference.

[17]  Z. Iqbal,et al.  Polarized Raman scattering and low frequency infrared study of hydroxyapatite , 1977 .

[18]  Yong Han,et al.  Effects of a Modified Sandblasting Surface Treatment on Topographic and Chemical Properties of Titanium Surface , 2001, Implant dentistry.

[19]  P. Tengvall,et al.  An in-vitro study of H2O2-treated titanium surfaces in contact with blood plasma and a simulated body fluid , 1993 .

[20]  A. Durán,et al.  Coatings produced by electrophoretic deposition from nano-particulate silica sol–gel suspensions , 2004 .

[21]  A. Matthews,et al.  Deposition of layered bioceramic hydroxyapatite/TiO2 coatings on titanium alloys using a hybrid technique of micro-arc oxidation and electrophoresis , 2000 .

[22]  L L Hench,et al.  Structural evaluation of human and sheep bone and comparison with synthetic hydroxyapatite by FT-Raman spectroscopy. , 1995, Journal of biomedical materials research.

[23]  Hsueh-Chuan Hsu,et al.  Surface modification of a Ti–7.5Mo alloy using NaOH treatment and Bioglass® coating , 2010, Journal of materials science. Materials in medicine.

[24]  P. Chu,et al.  Surface modification of titanium, titanium alloys, and related materials for biomedical applications , 2004 .

[25]  Ion N. Mihailescu,et al.  Pulsed Laser Deposition of Hydroxyapatite Thin Films , 2007 .

[26]  Shinn-Jyh Ding,et al.  Properties and immersion behavior of magnetron-sputtered multi-layered hydroxyapatite/titanium composite coatings. , 2003, Biomaterials.

[27]  Y. Sakka,et al.  Bubble‐Free Aqueous Electrophoretic Deposition (EPD) by Pulse‐Potential Application , 2008 .

[28]  Larry L. Hench,et al.  Bioceramics: From Concept to Clinic , 1991 .