The objective of this study was to characterize the chemical and physical properties of bioactive ceramics prepared from an aqueous paste containing hydroxyapatite (HA) and beta tri-calcium phosphate (β-TCP). Prior to formulating the paste, HA and β-TCP were calcined at 800 °C and 975 °C (11 h), milled, and blended into 15%/85% HA/β-TCP volume-mixed paste. Fabricated cylindrical rods were subsequently sintered to 900 °C, 1100 °C or 1250 °C. The sintered specimens were characterized by helium pycnometry, X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), and inductively coupled plasma (ICP) spectroscopy for evaluation of porosity, crystalline phase, functional-groups, and Ca:P ratio, respectively. Mechanical properties were assessed via 3-point bending and diametral compression. Qualitative microstructural evaluation using scanning electron microscopy (SEM) showed larger pores and a broader pore size distribution (PSD) for materials sintered at 900 °C and 1100 °C, whereas the 1250 °C samples showed more uniform PSD. Porosity quantification showed significantly higher porosity for materials sintered to 900 °C and 1250 °C (p< 0.05). XRD indicated substantial deviations from the 15%/85% HA/β-TCP formulation following sintering where lower amounts of HA were observed when sintering temperature was increased. Mechanical testing demonstrated significant differences between calcination temperatures and different sintering regimes (p < 0.05). Variation in chemical composition and mechanical properties of bioactive ceramics were direct consequences of calcination and sintering.
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Witek, L., Smay, J., Silva, N.R.F.A. et al. Sintering effects on chemical and physical properties of bioactive ceramics. J Adv Ceram 2, 274–284 (2013). https://doi.org/10.1007/s40145-013-0072-y
- bone graft material
- chemical/physical characterization
- bi-phasic calcium phosphate (BCP)