The crystallisation of glasses from the ternary CaF2-CaAl2Si2O8-P2O5 system
The crystallisation of glasses from the ternary CaF2-CaAl2Si2O8-P2O5 system
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DOI：
10.1023/a:1017974306184
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发表时间：
2001-08-01
影响因子：
4.5
通讯作者：
Wood, DJ
中科院分区：
文献类型：
--
作者：
Clifford, A;Hill, RG;Wood, DJ
对CaF_2-CaAl_2Si_2 O_8-P_2 O_5三元系统玻璃进行了研究。结果表明，低磷高氟石的玻璃结晶为氟石。氟可以降低玻璃化转变温度，也是氟磷灰石（FAP）形成所必需的。在玻璃中不存在氟的情况下，不形成磷灰石相。FAP的本体成核有利于Ca：P比接近磷灰石化学计量比1.67且具有低交联密度的玻璃。热重分析表明，显著的重量损失归因于挥发性四氟化硅的形成，发生在含铝相、钙长石和莫来石的结晶上，这支持了四氟化硅的形成被氟键合到玻璃网络的铝原子上所阻碍的观点。钙长石结晶总是发生的表面成核机制，并出现在这些玻璃中的较高的硅铝比相比，以前研究的玻璃组合物的青睐。(C)2001 Kluwer Academic Publishers.
A study of glasses from the ternary system CaF2-CaAl2Si2O8-P2O5 has been carried out. It has been shown that glasses with low phosphorus contents and high fluorite contents crystallise to fluorite. Fluorine reduces the glass transition temperature and is also required for the formation of fluorapatite (FAP). In the absence of fluorine in the glass no apatite phase is formed. Bulk nucleation of FAP is favoured for glasses with Ca:P ratios close to the apatite stoichiometry of 1.67 and with low crosslink densities. Thermal gravimetric analysis showed significant weight losses attributable to the formation of volatile silicon tetrafluoride to occur on crystallisation of the aluminium containing phases, anorthite and mullite, which supports the view that silicon tetrafluoride formation is hindered by fluorine bonding to the aluminium atoms of the glass network. Anorthite crystallisation always occurred by a surface nucleation mechanism and appeared to be favoured by the higher silicon to aluminium ratio in these glasses compared to previously studied glass compositions. (C) 2001 Kluwer Academic Publishers.