Fe_(2)O_(3)含量及晶化工艺对无碱铝硅玻璃弹性模量的影响

Effects of Fe_(2)O_(3) Content and Crystallization Process on Elastic Modulus of Alkali-Free Aluminosilicate Glass

选用CaO-MgO-Al_(2)O_(3)-SiO_(2)(CMAS)体系无碱铝硅玻璃为研究对象,设计8组Fe_(2)O_(3)组分变量,利用高温熔融法制备试验样品。利用XRD、SEM、TG-DSC等测试方法,先后对无碱玻璃样品的物相、析晶动力学、析晶行为和弹性模量等物化性能进行测试分析,进而探讨Fe_(2)O_(3)含量及晶化处理对无碱玻璃弹性模量的影响。结果表明:适量添加Fe_(2)O_(3)可以提升CMAS体系无碱玻璃的弹性模量,Fe_(2)O_(3)的质量分数为1.50%(F-6#)时,F-6#无碱玻璃弹性模量最大值为97.87 GPa,析晶活化能为347.1 kJ/mol,析晶指数n为1.383 4,为表面析晶。经整体析晶法晶化处理后,F-6#微晶玻璃析出的主晶相为钙长石相(CaAl_(2)Si_(2)O_(8)),晶体尺寸为200~400 nm;经烧结法晶化处理后,F-6#微晶玻璃析出的主晶相为钙长石相(CaAl_(2)Si_(2)O_(8)),晶体尺寸为300~500 nm。随着热处理温度的升高,析出主晶相数量变多,尺寸变大,但主晶相种类并未改变。由于钙长石的弹性模量小于基础玻璃,F-6#无碱玻璃析晶后所得微晶玻璃样品的弹性模量有所降低。

In this work,CaO-MgO-Al_(2)O_(3)-SiO_(2)(CMAS) system alkali-free aluminosilicate glass was selected as the research object.Eight groups of Fe_(2)O_(3) component variables were designed,and the experimental samples were prepared by high temperature melting method.XRD,SEM,TG-DSC and other test methods were used to tested and analyzed the phase,crystallization kinetics,crystallization behavior and elastic modulus of alkali-free glass samples,and then the effects of Fe_(2)O_(3) content and crystallization treatment on the elastic modulus of alkali-free glass were discussed.The results show that the appropriate addition of Fe_(2)O_(3) improves the elastic modulus of CMAS system alkali-free glass.When the mass fraction of Fe_(2)O_(3) is 1.50%(F-6#),the maximum elastic modulus of F-6# alkali-free glass is 97.87 GPa,the crystallization activation energy is 347.1 kJ/mol,and the crystallization index n is 1.383 4,which is surface crystallization.After crystallization treatment by bulk crystallization method,the main crystalline phase precipitated from F-6# glass-ceramics is anorthite phase(CaAl_(2)Si_(2)O_(8)),and the crystal size is 200~400 nm.After crystallization treatment by sintering method,the main crystalline phase precipitated from F-6# glass-ceramics is anorthite phase(CaAl_(2)Si_(2)O_(8)),and the crystal size is 300~500 nm.With the increase of heat treatment temperature,the number and size of the precipitated main crystal phase increase,but the type of the main crystalline phase keeps unchanged.However,because the elastic modulus of anorthite is smaller than that of the base glass,the elastic modulus of the glass-ceramics obtained after crystallization of F-6# alkali-free glass decreases.