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Monday, May 15, 2006 - 11:30 AM
BIC2.3

Characterization of LVOF Sprayed Hydroxyapatite Coating

S. Modi, A. Modi, G. R. Rayudu, Metallizing Equipment Co Pvt Ltd, Jodhpur, India

Hydroxyapatite (HA) coatings have proven biocompatible properties that can promote ontogenesis or new bone formation.  One of the effective and economical ways to coat HA is through thermal spray route.  However the conventional thermal spray coating processes like the Plasma spraying or High Velocity Oxy Fuel (HVOF) coating were observed to have altered the phase composition of the coating.  Moreover to improve the adhesion of the coating with the substrate and to increase fracture toughness of coating, the powder is required to be doped with zirconia, alumina or titania.  However, not much work is reported on the effect of these particles on human tissues when they come out of the coating due to regular wear and tear.  Hence a new LVOF coating system was developed to effectively deposit (without any doping) HA.  The developed coating was analyzed using Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and Young’s modulus and related mechanical properties were determined using Nano-indentation technique and three-point bend test.  This paper would discuss the mechanical behavior of the coating in retrospect to its suitability for bio medical applications.


Summary: Hydroxyapatite coatings have proven biocompatibility. Thermal spray is the most economical way to deposit HA coating. But the major problem associated with these is that phase change occurs in HA while being sprayed. In addition, resultant coating is not mechanically strong and doping is required. Hence we at MEC made an attempt to deposit the same using a modified LVOF system.