BaO-Al2O3-SiO2微晶玻璃密度的计算

为了评估密度作为BaO-Al2O3-SiO2(BAS)微晶玻璃晶化热处理和质量监控手段的可行性和准确性,提出一种测定微晶玻璃密度的方法.利用x射线衍射和Rietveld结构精修法准确测定烧结制备的BAS微晶玻璃中各晶相的质量分数和密度,研究了加和法则应用于BAS系微晶玻璃的准确性.对比精修得到的晶相的晶胞参数和对应标准卡片上纯晶相的晶胞参数,得到样品中各晶相的密度.结果表明:BAS微晶玻璃中各晶相与对应纯晶相的密度差别极其微小.利用获得的各相的质量分数,根据玻璃工艺学的经验数据计算残余玻璃相的密度.最后,根据加和法则计算得到BAS微晶玻璃样品的密度,所得的密度值与利用Archimedes法测得的密度值的相对偏差小于1.4%.

CALCULATION OF DENSITY IN BaO-Al2O3-SiO2 GLASS-CERAMICS

In order to estimate the feasibility of applying different densities in crystallization heat treatment and quality control for BaO-Al2O3-SiO2(BAS)glass-ceramics,a method for determining the density and porosity of glass-ceramics was proposed.X-ray diffraction and Rietveld analysis were used to identify and quantify the crystal phases in two types of BAS glass-ceramics samples that were prepared by different sintering processes.The density additivity and its precise degree used in the glass-ceramics were studied.By comparing refined lattice parameters and standard lattice parameters of crystal phases,the density of each crystal phase was cal-culated.The difference between the experimental and theoretical values of the density of each crystal phase in the glass-ceramics is negligible.According to the two-phase model,the densities of the samples were calculated by using the mass fractions of crystal phases and the remaining glass in the glass-ceramics samples.The maximum deviation is less than 1.4% in the experimental range between the calculated densities and the tested ones using the Archimedes method.