Sintering Behavior of Zirconia-hydroxyapatite Composite Powder

The mixed-powder of Ca3(PO4)2 and Ca(OH)2 in different proportions with different ZrO2 powder contents was made into slurry.The hydroxyapatite(HA) was obtained after the pressed milled slurry was pre-sintered.ZrO2/HA composite powders were synthesized at different sintering temperatures,which phaseds were analyzed by using XRD.The results show that β-Ca3(PO4)2 and t-ZrO2 phases were formed in the ZrO2/HA composite powder after sintering the raw material powders at 1 000 ℃ for 4 h.After sintering at 1 050-1 350 ℃ for 4 h,the composite with lower ZrO2 content (<10%) sintered at relative high temperature (>1 200 ℃),CaZrO3 phase was found.And the composite with higher ZrO2 content (>30%),t-ZrO2 phase amount increased as CaZrO3 phase amount decreased at each temperature period.In 1 050-1 200 ℃,HA decomposed faster and t-ZrO2 stability was improved.In 1 200-1 300 ℃,HA stopped decomposing.No ideal ZrO2/HA composite was obtained ,which was caused of various phases forming that leading to a overall reduced density as compared to that of pure HA.