Devitrification studies of wollastonite-tricalcium phosphate eutectic glass

Area of Science:

• Materials Science
• Ceramics Engineering
• Biomaterials Science

Background:

• Wollastonite-tricalcium phosphate (W-TCP) glasses are precursors to advanced bio-glass-ceramics.
• Understanding the devitrification and crystallization behavior is crucial for controlling material properties.

Purpose of the Study:

• To investigate the in situ devitrification and crystallization of W-TCP eutectic glass.
• To characterize the resulting bio-glass-ceramic microstructures and phases.
• To explore the influence of thermal treatments on phase formation.

Main Methods:

• In situ neutron diffractometry up to 1375°C in vacuum.
• Differential thermal analysis in ambient atmosphere.
• X-ray diffraction (XRD) and field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDS) on fired samples.

Main Results:

• Devitrification initiated around 870°C with Ca-deficient apatite crystallization.
• Wollastonite-2M (CaSiO(3)) crystallized at approximately 1006°C.
• At 1375°C, the bio-glass-ceramic comprised pseudowollastonite (CaSiO(3)) and alpha-tricalcium phosphate (Ca(3)(PO(4))(2)) in eutectic structures.

Conclusions:

• The W-TCP eutectic glass undergoes distinct phase transformations during heating.
• Tailored thermal treatments allow for the synthesis of diverse bio-glass-ceramics from the W-TCP system.
• Control over crystalline phases is achievable through precise thermal processing.