Vacuum plasma spray deposition of titanium particle/glass-ceramic matrix biocomposites

The vacuum plasma spray technique (VPS) has been successfully employed to coat Ti-6Al-4V substrates with bioactive glasses and Ti-particle/glass-ceramic matrix biocomposites, The composites were prepared by sintering, under an Ar flow, green bars of bioactive glass powders and 30% volume Ti particles, The bioactive glasses have the two following compositions: SCB (48.8SiO(2)-48.8CaO-2.4B(2)O(3)) and TSCB (46.6SiO(2)-48.7CaO-2.5B(2)O(3)-2.2TiO(2)) (mol %). The VPS bioactive coatings were characterized by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and mechanical tests (Vickers indentations and tensile and shear tests), Their bioactivity was tested by soaking the samples in a simulated body fluid (SBF) and by analyzing the growth of hydroxylapatite (HA) by SEM, EDS, and XRD, Leaching tests of Ca, Si, and P in SBF were made by inductively coupled plasma-atomic emission spectroscopy (ICP-AES, Perkin-Elmer 5000) to study the in vitro bioactivity of the samples versus time. Each coating was found to be bioactive and well bonded to the substrate; the composites showed better mechanical properties than the pure glass matrices and the hydroxylapatite coatings deposited by the same VPS technique.