Synthesis and characterization of xMgO-1.5Al2O3-5SiO2 (x = 2.6-3.0) system using mainly talc and kaolin through the glass route
Synthesis and characterization of xMgO-1.5Al2O3-5SiO2 (x = 2.6-3.0) system using mainly talc and kaolin through the glass route
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DOI：
10.1016/j.matchemphys.2011.05.026
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发表时间：
2011-10
影响因子：
4.6
通讯作者：
J. Banjuraizah;H. Mohamad;Z. Ahmad
中科院分区：
文献类型：
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作者：
J. Banjuraizah;H. Mohamad;Z. Ahmad
以滑石粉和高岭土为主要原料，采用玻璃化法合成了三种组成为xMgO-1.5Al_2 O_3 - 5SiO_2（x=2.6-3.0mol）的非化学计量比堇青石。利用差热分析仪、X射线衍射仪和X射线衍射仪研究了这些玻璃粉的致密化和晶化行为。然后将样品在900°C下热处理2小时，并使用XRD、CTE、FESEM、密度和孔隙率测试以及介电测试进一步分析以进一步研究它们的性质。在热处理温度下，2.8MgO·1.5Al2O3·5SiO 2玻璃完全致密化并晶化为高纯α-堇青石。与其他组合物相比，它表现出较低的CTE和介电常数，使其适用于高频应用。含有多晶相的其它配方需要高得多的温度来致密化。CTE值取决于样品中存在的晶相的类型，而介电常数随着样品组合物中MgO量的增加而降低。
Three non-stoichiometric cordierite with compositions of xMgO–1.5Al2O3–5SiO2(x=2.6–3.0mol) were synthesized using mainly talc and kaolin through the glass route. The densification and crystallization behaviors of these glass powders were investigated using DTA, dilatometer, and XRD. Samples were then heat treated at 900°C for 2h and further analyzed using XRD, CTE, FESEM, density and porosity tests, and also dielectric test to further investigate their properties. The 2.8MgO·1.5Al2O3·5SiO2glass composition fully densified and crystallized into high purity α-cordierite at the heat treatment temperature. It exhibited lower CTE and dielectric constant compared to other composition, making it suitable for high frequency applications. Other formulations which contain multi crystalline phases require much higher temperatures for densification. The CTE value depends on the type of crystalline phase which exist in the sample, while the dielectric constant decreased with increasing MgO amounts in the sample compositions.