摘要
研究了SiO_2-Al_2O_3-B_2O_3-MgO-MgF_2-K_2O系统金云母(KMg_3[AlSi_3O_(10)]F_2)可切削微晶玻璃制备工艺。通过玻璃的热膨胀曲线、差热分析、梯温析晶的测定,摸索了该系统玻璃的热处理制度:核化温度为600～650℃,晶化温度为1000～1100℃,保温10h。此种玻璃在100℃时体积电阻率为10^(15)Ω·cm,介电损耗为4.1×10^(-3)。用偏光显微镜、透射电子显微镜、X射线衍射探讨了其显微结构。提高晶体的径厚比和结晶率可提高其切削性和电绝缘性。阐述了其可切削性的机理。
The preparation procedure of machinable phlogopite glass ceramics (SiO_2-Al_2O_3-B_2O_3-MgO-MgF_2-K_2O system) is studied. Heat treatment procedure is determined by the analysis of thermal expansion, DTA curves and devitrification characteristics of the parent glass. The glass is nucleated at 600～350℃ followed by heat treatment at 1000～1100℃ for 10h as the crystallisation stage. The volume electrical resistivity (at 100℃) of the phlogopite based glass-ceramics is 10^(15) Ω.cm. The dielectric loss is 4.1×10^(-3). The microstructure of the material is observed by polarization microscopy, TEM and XRD. With increasing crystallinity and aspect ratio of crystals, the machinability and the electrical insulation properties of the material are improved. The mechanism of the machinability is also discussed.
关键词
金云母
微晶玻璃
可切削性
电绝缘
phlogopite
machinability
glass-ceramic
microstructure
electrical insulation
