Abstract
Effects of Ca/P ratio on the crystallization of apatite and anorthite were investigated by differential thermal analysis (DTA) and scanning electron microscopy (SEM) on a series of glasses with the nominal composition of 3.0 mass% MgO, 41.4 mass% SiO2, 8.6 mass% Al2O3, and 47 mass% (CaO+P2O5). It is shown that the activation energy for apatite crystallization decreases with increasing CaO content, whereas for anorthite crystallization it is not affected by changing Ca/P ratio significantly. Liquid phase separation was found in these glasses and the P2O5 promoted the nucleation appreciably.
