The Effects of Calcium Fluoride Addition on Crystallization Characteristics of Hydroxyapatite-Zirconia Composite

Abstract:

Hydroxyapatite (HA) doped with 3% Yttria-stabilized 20vol%m-ZrO₂ composite were synthesized by solid state reaction between tricalcium phosphate (TCP) and Ca(OH)₂ at various temperature(1000 to 1200°C) for 3h with adding 5~20wt% calcium fluoride (CaF₂), respectively. The effects of various amount of CaF₂ on crystallization characteristics of HA-20vol%ZrO₂ composite were investigated in details. The results show that when small amount of CaF₂ was added, the reactions of HA with CaF₂ occurs, which leads to the formation of fluorapatite (FA). With the increasing of the amount of CaF₂, the decomposition of HA to β-TCP decreases gradually and the CaZrO₃ peaks disappear, while t-ZrO₂ increases because of the formation of thermally stable FHA solid solutions. When the sintered temperature is above 1100°C and the addition of CaF₂ is about 10wt%, the main phases are FHA and t-ZrO₂ with a negligible amount of Ca₅P₈, which suppress the reaction between HA and ZrO₂. From SEM, it can be seen that with 10wt% of CaF₂ addition, the morphology of the composite powder is a mixture of spherical ZrO₂ particles embedded within agglomerated HA shaped like a small rod.

• Periodical: Advanced Materials Research (Volumes 197-198)
• Pages: 74-78
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.197-198.74
• Online since: February 2011
• Authors: Li Li Wang, Xiu Feng Wang, Jian Feng Zhu, Cheng Long Yu
• Keywords: Calcium Fluoride, Crystallisation Characteristic, Fluorapatite, HA-ZrO₂ Composite

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