Composite (biphasic) mixtures of two of the most important
inorganic phases of synthetic bone applications—namely,
calcium hydroxyapatite (Ca10(PO4)6(OH)2 (HA)) and tricalcium
phosphate (Ca3(PO4)2 (TCP))—were prepared as
submicrometer-sized, chemically homogeneous, and highpurity
ceramic powders by using a novel, one-step chemical
precipitation technique. Starting materials of calcium nitrate
tetrahydrate and diammonium hydrogen phosphate
salts that were dissolved in appropriate amounts in distilled
water were used during powder precipitation runs. The
composite bioceramic powders were prepared with compositions
of 20%–90% HA (the balance being the TCP phase)
with increments of 10%. The pellets prepared from the
composite powders were sintered to almost full density in a
dry air atmosphere at a temperature of ~1200°C. Phaseevolution
characteristics of the composite powders were
studied via X-ray diffractometry as a function of temperature
in the range of 1000°–1300°C. The sintering behavior
of the composite bioceramics were observed by using scanning
electron microscopy. Chemical analysis of the composite
samples was performed by using the inductively coupled
plasma–atomic emission spectroscopy technique.