SiO_(2)/Al_(2)O_(3)摩尔比对堇青石微晶釉结构与性能的影响

Influences of SiO_(2)/Al_(2)O_(3) Molar Ratio of The Structure and Properties of Cordierite Glaze

以矿物为主要原料采用生料釉法制备堇青石微晶釉,探究了不同SiO_(2)/Al_(2)O_(3)摩尔比对堇青石微晶釉结构和性能的影响。通过高温显微镜、XRD、FT-IR、SEM等对堇青石微晶釉进行了测试表征,并测试其热膨胀系数、釉面硬度和白度。结果表明:随着SiO_(2)/Al_(2)O_(3)摩尔比从7.7降低到3.5,釉的流动性先提高后降低,釉中存在的主晶相由单一顽火辉石转变为顽火辉石和α-堇青石共存再到单一α-堇青石最后转变为α-堇青石和镁铝尖晶石。且釉中α-堇青石含量先增加后减少,热膨胀系数先降低后升高,釉面硬度先增大后减小,白度先减小后增大;当SiO_(2)/Al_(2)O_(3)摩尔比为4.0时,样品的综合性能最佳,α-堇青石含量最高,为19.8%,釉的热膨胀系数为4.37×10^(-6)(600℃),釉面硬度为6.9 GPa,白度为69.1 Wb。

This experiment uses minerals as the main raw material to prepare cordierite microcrystalline glaze by the raw glaze method,and explores the influences of different SiO_(2)/Al_(2)O_(3) molar ratios on the structure and properties of cordierite microcrystalline glaze.The cordierite microcrystalline glaze was tested and characterized by high temperature microscope,XRD,FT-IR,SEM,etc.,and its thermal expansion coefficient,glaze hardness and whiteness were tested.The results show that as the SiO_(2)/Al_(2)O_(3) molar ratio decreases from 7.7 to 3.5,the fluidity of the glaze first increases and then decreases,the main crystalline phase existing in the glaze changes from a single enstatite to enstatite andα-cordierite coexisting and then to a singleα-cordierite finallyα-cordierite and magnesia-aluminum spinel.And the content ofα-cordierite in the glaze first increases and then decreases,the coefficient of thermal expansion first decreases and then increases,the hardness of the glaze first increases and then decreases,and the whiteness first decreases and then increases.When the SiO_(2)/Al_(2)O_(3) molar ratio is 4.0,the overall performance of the sample is the best,theα-cordierite content is the highest,reaching 19.8%,the thermal expansion coefficient is 4.37×10^(-6)(600℃),the glaze hardness is 6.9 GPa,and the whiteness is 69.1 Wb.