等温处理过程中杆状氟闪石晶体的长大

Growth of Rod-like Fluoramphibole Crystals during Isothermal Treatment Processing

将氟云母晶体粉末与普通窗玻璃粉末混合烧结制备成氟闪石玻璃陶瓷,氟闪石晶体是通过氟云母和玻璃间的反应析出,而不是以分相、形核、长大的方式从母相玻璃中析出。用X射线衍射仪和扫描电镜测定了860℃等温过程中氟闪石晶体的析晶量、平均直径、直径分布和数量,对晶体长大规律进行了研究。结果表明,氟闪石晶体长大分两步进行。在第一阶段,氟闪石晶体析出和长大同时进行;在第二阶段,氟闪石晶体停止析出,晶体以大晶粒吞食小晶粒的方式长大,长大规律符合Ostwald熟化机制。

A fluoramphibole glass-ceramic was fabricated by mixing fluormica crystals and recycled glass powders and then sintering,the fluoramphibole crystals were precipitated by an interaction between fluormica crystals and glass powders instead of by separation of phase,nucleation and growth from parent glass.The growing mechanism of fluoramphibole crystals was investigated through the measurement of crystallinity,mean diameter,diameter distribution and number of fluoramphibole crystals using X-ray diffraction and scanning electron microscope during isothermal treatment at 860 ℃.The results show that the growth of fluoramphibole crystals could be divided into two stages.In the first stage,precipitation and growth of fluoramphibole crystals carry out simultaneously;but in the second stage,the precipitation of fluoramphibole crystals ceases,the crystals grow in the form that bigger crystals swallow smaller ones,and the growing mechanism consists with the Ostwald ripening.