低熔化温度可切削玻璃陶瓷的成分研究

Composition Study of Machinable Glass Ceramics with Low Melting Temperature

低熔点氧化物Li2O和ZnO使SiO2-Al2O3-MgO-K2O-B2O3-Li2O-ZnO-F系的熔化温度和析晶温度大大降低。ZnO还有扩大玻璃形成区的作用,使较高Li2O含量的玻璃可以获得透明。通过优选SiO2,Al2O3和MgO的成分,得到的玻璃陶瓷中除有足够数量的互相搭接良好的云母晶体外,还可以获得堇青石的晶体,它们分布在的云母晶体之间,使玻璃相减少。从而减小了晶体间的平均自由程,提高了可切削玻璃陶瓷的强度。

The composition of machinable glass ceramics in the SiO2-Al2O3-MgO-K2O-B2O3-Li2O-ZnO-F system has been studied in order to decrease their melting temperature and to increase their strength at the same time.. The results show that the melting temperature and the crystallizing temperature are decreased because of adding low melting-point oxides Li2O and ZOO. ZOO can expande the forming area of glass and make the glass with higher content of Li2O transparent. At the optimizing composition of SiO2, Al2O3 and MgO, cordierite is formed among mica crystals contacted each other, and the glass phase is decreased. Thus the mean free path between crystals is decreased, which results in the high strength of the machinable glass ceramic.