CaO含量对铝硼硅玻璃理化性能的影响与机理

以SiO2、B2O3、Al2O3及碱土金属氧化物(MgO、CaO、SrO)为原料,利用高温熔融法制备无碱铝硼硅玻璃。研究不同CaO含量对无碱铝硼硅玻璃性能和结构影响作用规律。对玻璃进行了热综合分析(DSC)、耐化学稳定性和密度的性能测试,通过红外光谱(FTIR)和X射线光电子能谱(XPS)对玻璃试样进行网络结构分析。研究表明,玻璃的析晶区间面积随着CaO含量的增加,由3.7 J/g升高到15.03 J/g,AlO6]和BO4]的出现会导致玻璃网络结构疏松,玻璃的析晶倾向增强;玻璃的被酸侵蚀由3.6817 mg/cm2增加到4.2609 mg/cm2,玻璃被碱侵蚀由1.4199 mg/cm2降低到1.0907 mg/cm2,碱侵蚀的过程中生成的一层硅酸钙薄膜阻碍了反应的进行;随着CaO含量的增加,玻璃中的非桥氧含量增加,会促使AlO4]向AlO6]转变,CaO含量继续增加还会使BO3]向BO4]转变。

Effect and Mechanism of CaO Content on Physical and Chemical Properties of Alkali-free Aluminoborosilicate Glass

Alkali-free aluminoborosilicate glass was prepared from SiO2,B2 O3,Al2 O3 and alkaline earth metal oxide(RO) by high temperature melting method.The effect of different CaO content on the properties and structure of alkali-free aluminoborosilicate glass was studied.The thermal analysis(DSC),chemical stability and density of the glass were tested and the network structure of glass samples was analyzed by FTIR and XPS.Studies have shown that the area of crystallization interval of glass increases from 3.7 J/g to 15.03 J/g with the increase of CaO content.AlO6] and BO4] will lead to loose glass network structure and enhanced crystallization tendency of glass.The acid erosion of glass increased from 3.6817 mg/cm2 to 4.2609 mg/cm2,and the alkali erosion of glass decreased from 1.4199 mg/cm2 to 1.0907 mg/cm2.In the process of alkali erosion,a layer of calcium silicate film was formed,which hindered the reaction.With the increase of CaO content,the increase of non-bridging oxygen content in the glass will promote the transition from AlO4] to AlO6],and the continuous increase of CaO content will also cause the transition from BO3] to BO4].