Sintering behaviour of diopside (CaO∙MgO∙2SiO2)–fluorapatite (9CaO∙3P2O5∙ CaF2) bioactive glass

• We examine the sintering behaviour of an alkali-free bioactive glass.
• We study the influence of particle size variation on sintering ability.
• The content of residual glassy phase increases as mean particle size increases.
• The coarsening of glass particles retards the densification process.

The sintering behaviour of an alkali-free bioactive glass with its chemical composition corresponding to 80 wt.% diopside (CaMgSi2O6)–20 wt.% fluorapatite [Ca5(PO4)3F] has been reported in this article. Glass powders with different particle size distributions and mean particle sizes varying between 14 μm and 220 μm were used. The influence of particle size variation on sintering ability of glass powders was studied by using an array of complementary advanced characterization techniques including in situ high temperature scanning electron microscopy (HT-SEM), differential thermal analysis (DTA), hot stage microscopy (HSM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The obtained results have been discussed with their implications on the development of glass–ceramic scaffolds for bone tissue engineering. Glass–ceramics consisting of dense glassy matrix with embedded diopside and fluorapatite crystals were obtained after sintering the glass powder compacts at 850 °C for 1 h.