纳米氧化镱对熔融石英析晶动力学机制的影响

本文研究引入纳米氧化镱对熔融石英析晶机制及动力学过程的影响。通过X射线衍射仪(XRD)测试结果分析了纳米氧化镱的引入对熔融石英陶瓷析晶率的影响,采用动力学方法分析了纳米氧化镱的引入对熔融石英陶瓷析晶机制的影响,同时探讨了其等温析晶动力学过程。研究表明,熔融石英陶瓷的晶粒向二维兼有一维及三维的方式生长,引入纳米氧化镱的熔融石英陶瓷的晶粒则向二维兼有三维的方式生长;试样B和试样Y的析晶活化能E分别为874 kJ/mol和1 188 kJ/mol。在熔融石英陶瓷中引入纳米氧化镱能够大幅度减少SiO₂玻璃脱玻为方石英的“活性成核点”,增加玻璃表面结构稳定性,提高析晶活化能,大大降低熔融石英的析晶率。

Effect of Nano-Yb2O3 on Crystallization Kinetics Mechanism of Fused Quartz

The effect of nano-Yb₂O₃ on the crystallization mechanism and kinetics of fused quartz were studied. The effect of nano-Yb₂O₃ on crystallization ratio of fused quartz ceramics was studied by means of XRD, and the effect of nano-Yb₂O₃ on the crystallization mechanism of fused quartz ceramics was studied by kinetic method, meanwhile, the isothermal crystallization kinetics of two kinds of fused quartz ceramics were discussed. The results show that the grain growth mode of fused quartz ceramics is two-dimensional growth accompanied by one-dimensional and three-dimensional growth, while the grain growth mode of fused quartz ceramics with nano-Yb₂O₃ is two-dimensional accompanied by three-dimensional growth. The activation energy E of samples B and samples Y are 874 kJ/mol and 1 188 kJ/mol, respectively. With the introduction of nano-Yb₂O₃ in fused quartz ceramics, the "active nucleation point" of SiO₂ glass for cristobalite reduce greatly, the stability of the glass surface structure increases, the crystallization activation energy increases, and the crystallization ratio of fused quartz reduces greatly.