A physico-chemical study of crystal growth of hydroxyapatite bioceramic

Synthetic hydroxyapatite powders were pressed and fired at different temperatures for varying time intervals. Fired samples were fractured and the surface produced was examined by SEM. Four kinds of crystal growth has been seen, grains (principally) lamellae, dendritic interlacings and efflorescences and large hexagonal crystals. Evaluation of trends in activation energy permitted a determination of the temperatures at which phase transformation occurred and discussion of the competing processes involved. The studies confirmed that the optimum firing temperature is between 1100 degrees and 1150 degrees C.