晶核剂对镁铝硅微晶玻璃析晶行为的影响

Effects of Nucleation Agents on the Crystallization Behavior of Magnesium Aluminosilicate Glass-ceramics

在MgO-Al_2O_3-SiO_2系统玻璃中分别引入TiO_2、ZrO_2作为晶核剂,采用"两步法"热处理制备微晶玻璃,并研究晶核剂对其析晶行为的影响。实验结果表明,以TiO_2为晶核剂时,MAS玻璃析晶峰温度较低,析晶速率较慢,易于可控析晶,当热处理制度为770℃/4h+950℃/2h,微晶玻璃中析出MgTi_2O_5与MgAl_2O_4两种晶相,且微晶玻璃外观透明。以ZrO_2作为晶核剂时,MAS玻璃析晶峰温度升高,析晶速率增加,在830℃/4h+1 000℃/2h热处理后,析出镁铝硅酸盐及ZrO_2晶体,其中镁铝硅酸盐与β-石英结构类似。

Using TiO_2/ZrO_2 as nucleation agents,MgO-Al_2O_3-SiO_2glass-ceramics were prepared by the＂two-steps＂heat treatments,and the effects of the nucleating agents on the crystallization behavior of glass-ceramics were investigated.When TiO_2 was added as nucleation agent,the crystallization peak temperature is low and the crystallization rate is slow.When the heat treatment conditions were 770 ℃/4h＋950 ℃/2h,MgTi_2O_5 and MgAl_2O_4 were precipitated from glass matrix.When adding ZrO_2 as nucleating agents,the crytallization peak temperature and crystallization rate of MAS glasses increased.ZrO_2 and MgAl_2Si_3O_（10）formed in glass at 830 ℃/4h ＋ 1 000 ℃/2h,which possessed the similar structure withβ-quartz solid solution.