Fibrous growth of tricalcium phosphate ceramics.
Fibrous growth of tricalcium phosphate ceramics.
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磷酸三钙陶瓷的纤维生长。
DOI：
10.1023/a:1018512428683
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
V. P. Gortcheva
中科院分区：
文献类型：
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作者：
J. Valdés;J. O. López;G. Morales;G. Malagón;V. P. Gortcheva
采用x射线衍射（XRD）和原子力显微镜（AFM）研究了缺陷羟基磷灰石（Ca9HPO4(PO4)5OH）制备的磷酸三钙（TCP）陶瓷的结构转变和烧结过程。将0.5 l 0.3 M H3PO4溶液加入等体积的0.45 M Ca(OH)2中，得到Ca/P比为1.5的起始粉末。在所制备的陶瓷中，缺陷羟基磷灰石转变为TCP （witlokite）的起始温度与烧结的起始温度（800℃）一致。烧结是通过纤维结构的形成而发生的，这种结构类似于生物硬组织。在1000-1200°C范围内，这些纤维结合成0.6 μm大小的颗粒，具有纤维层状形态。在烧结阶段结束时，witlokite转变为αTCP。在1450℃左右，αTCP部分分解为Ca2P2O7+Ca4P2O9。AFM观察表明，Ca2P2O7在液相中偏析，晶粒生长速度加快（可达12 μm）。
Structural transformation and sintering processes of tricalcium phosphate (TCP) ceramics prepared from defective hydroxyapatite (Ca9HPO4(PO4)5OH) were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). Starting powders with Ca/P ratio ∼1.5 were obtained by adding 0.5 l of 0.3 M H3PO4 solution to an equal volume of 0.45 M Ca(OH)2. In the prepared ceramics, the onset temperature for transformation of defective hydroxyapatite into TCP (witlokite) agrees with the onset temperature for sintering (800 °C). Sintering occurs through the formation of a fibrous structure, which resembles biological hard tissue. In the 1000–1200°C range, these fibres coalesce into grains of up to 0.6 μm in size with a fibrous-laminar morphology. At the end of this sintering stage witlokite transforms into αTCP. At about 1450°C, partial decomposition of αTCP into Ca2P2O7+Ca4P2O9 is observed. AFM observations suggest that Ca2P2O7 is segregated in the liquid state and increases the velocity of grain growth (up to 12 μm).