Calcining influence on the powder properties of hydroxyapatite
Calcining influence on the powder properties of hydroxyapatite
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DOI：
10.1023/a:1008986430940
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发表时间：
2001-02
期刊：
影响因子：
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通讯作者：
N. Patel;I. Gibson;S. Ke;S. Best;W. Bonfield
中科院分区：
文献类型：
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作者：
N. Patel;I. Gibson;S. Ke;S. Best;W. Bonfield
研究了不同煅烧温度对合成羟基磷灰石（HA）粉末特性和烧结密度的影响。通过干燥、研磨和筛分沉淀的HA或通过喷雾干燥沉淀的HA的浆料来生产粉末。在400至1000 °C的温度下煅烧两种粉末不会显著影响粉末粒度。然而，这两种粉末的比表面积从400 °C煅烧温度下的70-80 m2/g降低到1000 °C下的约5-7 m2/g。使用扫描电子显微镜（SEM）的HA粉末的表面的分析示出的粗化和随后的烧结的亚微米微晶，构成粉末颗粒的煅烧温度增加，对应于在粉末的表面积的减少。煅烧粉末对最终陶瓷的烧结密度没有显著影响。显微硬度的测量结果表明，在不同温度下煅烧的粉末制备的陶瓷没有显着的变化与煅烧温度或粉末处理方法。本研究的结果已经说明，对于HA可以以粉末形式使用的应用，例如在等离子喷涂和用于HA-聚合物复合材料的生产中，煅烧HA将显著影响粉末性质，即粉末的表面积和形态。对于需要致密陶瓷形式的HA的应用，例如作为颗粒或块，煅烧粉末不会显著影响最终陶瓷的性质。
The effect of different calcination temperatures on the powder characteristics and the sintered density of synthetic hydroxyapatite (HA) powders, produced using two different processing routes, was examined. Powders were produced by either drying, milling and sieving an as-precipitated HA or by spray-drying a slurry of precipitated HA. Calcining the two powders at temperatures between 400 and 1000 °C did not significantly affect the powder particle size. The specific surface areas of the two powders, however, were reduced from 70–80 m2/g for a calcination temperature of 400 °C to approximately 5–7 m2/g for 1000 °C. Analysis of the surfaces of the HA powders using scanning electron microscopy (SEM) illustrated the coarsening and subsequent sintering of the sub-micron crystallites that constitute a powder particle as the calcination temperature increased, corresponding to the decrease in surface area of the powders. The sintered densities of the final ceramics were not significantly affected by calcining the powders. Microhardness measurements of ceramics prepared from powders calcined at different temperatures showed no significant variations with calcination temperature or powder processing method. The results of this study have illustrated that for applications where HA may be used in powder form, for example in plasma-spraying and for the production of HA-polymer composites, calcining the HA will significantly affect the powder properties, namely the surface area and morphology of the powders. For applications requiring HA in a dense ceramic form, for example as granules or blocks, calcining the powders does not significantly affect the properties of the final ceramic.