Figure 1.

The XRD patterns. (a) an initial HA powder, (b) as sprayed HA coatings, (c) air heat-treated at 600°C HA coatings (AH600) and (d) hydrothermally treated at 150°C HA coatings (HT150). It is easily seen that both the crystallinity and phase purity of poorly crystalline HA coatings increased after both heat and hydrothermal treatments. Reprinted from Yang et al. (2009a) with permission.