Abstract
Effects of the Al/P ratio on the crystallization of apatite and anorthite were investigated by differential thermal analyses on a series of glasses with the nominal composition of 3.0wt% MgO, 35.0wt% CaO, 41.4 wt% SiO2, and 20.6wt% (Al2O3+P2O5). It is shown that the activation energy for crystallization of apatite decreases with decreasing Al/P ratio, but that for crystallization of anorthite, on the contrary, increases. The Avrami parameter, n, was also estimated to be 2 and 1 for apatite and for anorthite, respectively.
