EFFECTS OF TRIVALENT AND PENTAVALENT VANADIUM SUBSTITUTION ON THE SINTERING CHARACTERISTICS AND MICROSTRUCTURE OF β-TRICALCIUM PHOSPHATE CERAMICS

The compound -tricalcium phosphate (-TCP) is widely used as a bioresorbable ceramic, but lacks mechanical strength and so has limited clinical applications.The present study substituted vanadium in either the trivalent (V) or pentavalent (V) states into this material and evaluated the effects on sintering behavior and microstructural evolution.Various -TCP ceramics having specific proportions of V and V were synthesized via a solid-state reaction process and subsequently characterized, using X-ray diffraction, Fourier-transform infrared spectroscopy, dilatometry, Archimedes' method, scanning electron microscopy and grain size measurements.All specimens were found to comprise a single-phase -TCP structure with the V incorporated at P sites as VO groups and the V occupying Ca sites.Increasing the V content promoted densification, reduced porosity and suppressed grain growth, leading to fine-grained, dense microstructures.In contrast, V substitution inhibited shrinkage and densification while facilitating grain coarsening and pore retention.These findings demonstrate that the valence state of the vanadium had a significant effect on the sintering characteristics and microstructural development.The complementary roles of V and V suggest a novel approach to tailoring the microstructure of this ceramic, thereby expanding the potential of -TCP as an advanced bioresorbable bone graft material.