粉体粒度对K2O-Al2O3-SiO2系微晶玻璃析晶动力学的影响

采用烧结法制备了K2O-Al2O3-SiO2系微晶玻璃.研究了不同粒度分布的玻璃粉对K2O-Al2O3-SiO2系微晶玻璃的析晶及对其性能的影响,进而优化制备K2O-Al2O3-SiO2系微晶玻璃的粉体粒度.结果表明:玻璃粉体的细化有利于析晶,玻璃粉体平均粒径从38.09 μm减小到1.80 μm时,微晶玻璃的析晶温度从913.9 ℃降低至869.9 ℃.析晶活化能从320.5 kJ/mol减小至234.7 kJ/mol.微晶玻璃的析出晶相均为白榴石,玻璃粉体平均粒径为6.30 μm时,微晶玻璃的微观结构较为均匀,密度为2.45 g·cm-3,抗弯强度为74.93 MPa,热膨胀系数为14.32×10-6 K-1.
K2O-Al2O3-SiO2 glass-ceramics were prepared by sintering method. The effects of glass powders with different particle size distribution on the crystallization and microstructure of K2O-Al2O3-SiO2 glass-ceramics were studied, so as to optimize the particle size of K2O-Al2O3-SiO2 glass-ceramics. The results show that the crystallization temperature of glass-ceramics decreases from 913.9 oC to 869.9 oC when the median particle size of glass powder decreases from 38.09 μm to 1.80 μm. Crystallization activation energy also decreased from 320.5 kJ/mol to 234.7 kJ/mol. The crystallized phase of the glass-ceramics are both leucite. When the median particle size of the glass powder is 6.30 μm, the microstructure of the glass-ceramics is more uniform. The glass-ceramics has a density of 2.45 g·cm-3, a flexural strength of 74.93 MPa, and a thermal expansion coefficient of 14.32×10-6 K-1.