Effect of magnesium ion (Mg2+) substitution and calcination to the properties of biphasic calcium phosphate (bcp)
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Date
2018-06
Authors
Mohamad Abdul Aziz Zahari
Journal Title
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Abstract
Magnesium-doped biphasic calcium phosphate (Mg-BCP) was successfully
synthesized via aqueous precipitation method at room temperature. The objectives are to
study the effect of substitution of magnesium ion and effect of calcination towards apatite
structure. As-synthesized BCP powder was used as a reference in this research work. The
as-synthesized Mg-BCP powder had been characterized via Thermogravimetry-Differential Scanning Calorimetry (TG-DSC), X-ray Diffraction (XRD), Fourier
Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron
Microscopy (FESEM). The as-synthesized Mg-BCP powder was then fabricated by
uniaxial pressing method to form a 13 mm diameter pellet and followed by calcination at
three different temperatures (600 °C, 700 °C and 800 °C) in normal atmosphere. The Mg-BCP pellets had been characterized by XRD (phase), volume shrinkage, bulk density
measurement, Vickers hardness test and FESEM (microstructure). The XRD result shows
that only HA phase was formed for BCP pellets. However, for Mg-BCP pellets, HA and
β-TCP mixture was successfully formed started at 700 °C. Thus, it is proved that the
substitution of Mg2+ into BCP able to lower the β-TCP phase transformation temperature.
Furthermore, by the formation of β-TCP, the hardness value of pellets dropped. Among
the Mg-BCP pellets, the bulk density and hardness values obtained for C6 Mg-BCP
(calcine at 600 °C) were 1.5534 g/cm3
and 43.8 HV, respectively and it showed that C6
Mg-BCP has better mechanical properties if compared to C7 Mg-BCP (calcine at 700 °C)
and C8 Mg-BCP (calcine at 800 °C). Therefore, the substitution of Mg2+ in apatite
structure and increasing calcination temperature will reduce the hardness value of Mg-BCP pellets