Papers by Author: X.B. Chen

Abstract: Titanium and some of its alloys are widely used as load-bearing implant materials. In particular, titanium-zirconium (Ti-Zr) alloys have a high potential for biomedical applications due to the excellent biocompatibility of both Ti and Zr. Nevertheless, the surfaces of the Ti-Zr alloys need to be modified to provide the implant material’s bioactivity. In the present study, an alkali-heat (AH) treatment process followed by the soaking in simulated body fluid (SBF) was attempted for the preparation of calcium phosphate (CaP) coatings on the surface of the TiZr alloy. Phase transformation, surface morphology, and interfacial microstructure were investigated using scanning electron microscope (SEM) with an energy-dispersive electron probe X-ray analyser (EDS). The results indicate that the AH treatment produced a nano-porous bioactive sodium titanate / zirconate hydrogel surface layer which induced the deposition of a Ca-P layer during soaking in the SBF. This Ca-P layer on the TiZr alloy surface can be expected to bond to the surrounding bones directly after implantation.

Abstract: Various types of titanium alloys with high strength and low elastic modulus and, at the same time, vanadium and aluminium free have been developed as surgical biomaterials in recent years. Moreover, porous metals are promising hard tissue implants in orthopaedic and dentistry, where they mimic the porous structure and the low elastic modulus of natural bone. In the present study, new biocompatible Ti-based alloy foams with approximate relative densities of 0.4, in which Sn and Nb were added as alloying metals, were synthesised through powder metallurgy method. The new alloys were prepared by mechanical alloying and subsequently sintered at high temperature using a vacuum furnace. The characteristics and the processability of the ball milled powders and the new porous titanium-based alloys were characterised by X-ray diffraction, optical microscopy and scanning electron microscopy .The mechanical properties of the new titanium alloys were examined by Vickers microhardness measurements and compression testing.