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| MgO/Al2O3比对MgO-Al2O3-SiO2系统玻璃分相与析晶的影响 |
| Effect of MgO/Al2O3 Ratio on Phase-separation and Crystallizationof MgO-Al2O3-SiO2 Glass |
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| DOI：10.11896/j.issn.1005-023X.2018.24.008 |
| 中文关键词: 镁铝比 分相 析晶 堇青石 |
| 英文关键词: MgO/Al2O3 ratio, phase-separation, crystallization, cordierite |
| 基金项目:包镇红:女,1982年生,博士研究生,副教授,主要从事传统陶瓷及应用研究江伟辉:通信作者,男,1965年生,博士,教授,主要从事低纤维材料及陶瓷材料的研究 E-mail:jwhjiang@163.com |
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| 中文摘要: |
| 采用高温熔融法制备了具有不同MgO/Al2O3比的堇青石微晶玻璃。采用差热分析仪(DTA)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)等测试技术研究了MgO/Al2O3比对该系统玻璃分相和析晶的影响。结果表明:当SiO2含量不变时,随着MgO/Al2O3比的减小,分相形貌由连通的蠕虫状逐渐变为孤立的球形结构,且分相粒子尺寸逐渐减小,从200~300 nm减小至30~50 nm。当MgO/Al2O3比从3降到1,析晶峰温度由997 ℃升至1 105 ℃,析晶的难度逐渐提高。当MgO/Al2O3比为3时,MgO-Al2O3-SiO2系统玻璃经950 ℃热处理后即产生大量分相,经1 050 ℃热处理后在分相液滴中析出大量堇青石晶体,且堇青石优先在富Mg相中析出。提高MgO/Al2O3比有利于MgO-Al2O3-SiO2系统玻璃在分相中析晶,反之,则会降低系统的分相和析晶能力。 |
| 英文摘要: |
| Cordierite-based glass-ceramics with diverse MgO/Al2O3 ratios were prepared by high temperature melting met-hod. The impact of MgO/Al2O3 ratio on the phase separation and crystallization behavior of the MgO-Al2O3-SiO2 glass were investigated by means of differential thermal analyzer (DTA), X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicated that with the constant content of SiO2, the decrease of MgO/Al2O3 ratios leaded to the morphology change of phase separation droplets from worm-like shape to isolated sphere,and the gradual size reduce of phase separation droplets from 200—300 nm to 30—50 nm. The increase of crystallization peak temperature (Tp) from 997 ℃ to 1 105 ℃could be observed as the MgO/Al2O3 ratio decreased from 3 to 1, which made the crystallization become more difficult. When the MgO/Al2O3 ratio is 3, the MgO-Al2O3-SiO2 glass would produce a large amount of phase separation droplets after heat treatment at 950 ℃. After heat treatment at 1 050 ℃, substantial cordierite crystals were precipitated in phase separation droplets, which were preferentially precipitated in Mg-rich phase. Increasing MgO/Al2O3 ratio was highly beneficial to the phase separation and crystallization in MgO-Al2O3-SiO2 glass. Conversely, reducing the MgO/Al2O3 ratio would weaken the the ability of phase separation and crystallization of the glass. |
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