Abstract: Hydroxyapatite powder particles were plasma sprayed into water, their inner structures and phase compositions were studied by using scanning electron microscope (SEM) and X-ray diffractometer. The results show that the molten HA particles have a central hollow morphology and high crystallinity. The hollow morphology was caused by sublimated P2O5 and H2O, which will have an effect on surface morphology, cohesive and adhesive strength as well as dissolution and degradation of coating. The high crystallinity is attributed to lower cooling speed in water.

Key words: Hollow morphology, Phase composition, Hydroxyapatite, Plasma spray