PROCESSING OF CALCIUM PHOSPHATE BASED FUNCTIONALLY GRADED BIOCERAMICS USING MICROWAVES

A functionally graded material (FGM) was fabricated by microwave processing by gradually changing the composition of calcium phosphates, titania and silver from the surface to the interior. Silver oxide (5 mol. %) and titania (anatase, 10 mol. %) were spread on the surface of compact hydroxyapatite (HA) pellet and exposed to microwave irradiation. The sintered samples were found to contain B-tricalcium phosphate (β-TCP), rutile titania and metallic silver (Ag) along with HA as indicated by X-ray powder diffraction (XRD) method. The content of TCP, titania and Ag gradually decreases with increasing depth from the surface. The FGMs formed by both microwave processing and by conventional heat treatment at 900°C for 12 h were compared. The presence of a small amount of calcium titanate was observed in both the FGMs. The microwave processed FGM indicated more amounts of titania and Ag on the surface and suggests the possibility of greater compositional control in FGM fabrication by microwave processing.