Abstract
Hydroxyapatite(HA), Ca10(PO4)6(OH)2, is one of the most biocompatible materials with human bones. HA is a promising bone substitute material for clinical application because of clinical stability in vivo. Fine powder of HA were heated at 900°C for 1 h and at 1000°C for 6 h in air. The first objective of this study is to reveal the effect of plastic flow on densification behavior by spark plasma sintering (SPS) from various preheated HA powders. From the isothermal shrinkage behavior, we concluded that the plastic flow in later stage does not depend on the preheating temperature. The second objective of this study is to prepare graduated HA ceramics for artificial bone by SPS. These heating powders (0.25 g) were vertically laminated into the graphite mold and then sintered by SPS at the temperatures from 800°C for 10 min with a heating rate of 25 K min-1• The ceramics prepared by SPS had pores of about 0.1 micro m after heated at 1000°C for 6 h. There were no pores in HA ceramics prepared by SPS before heated at 900°C for 1 h.
