Crystallization Kinetics of Calcium Aluminate Glasses Studied by Non-isothermal Techniques
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2013年第5期
论文作者：王衍行 ZU Chengkui HE Kun ZHAO Huifeng HAN Bin CHEN Jiang
文章页码：907 - 911
摘 要：The crystallization kinetics of 38.0CaO-38.0Al2O3-10.5BaO-6.5MgO-6.0Y2O3-1.0（Na2O+K2O）（wt%） glass was studied by differential scanning calorimeter（DSC） and X-ray diffraction（XRD） techniques.The results showed that DSC curves of calcium aluminate glass have a single glass transition temperature followed by one crystallization peak for the heating rates β=5 K/min and two crystallization temperatures Tp1 and Tp2 for β≥10 K/min.The activation energies of crystallization obtained from the Gao-Wang model of the first exothermal peak and the second exothermal peak of calcium aluminate glass are 340 and 662 kJ/mol,respectively.The Avrami exponents of the both crystallization peaks are approximately 2,indicating the twodimensional crystalline growth during its transformation from amorphous to crystalline.Ca12Al14O33,Ca3Al2O6 and unknown crystalline phases firstly appear when calcium aluminate glass is heat-treated.With the extending of heat-treatment duration,BaAl2O4 phase comes out.
王衍行，ZU Chengkui，HE Kun，ZHAO Huifeng，HAN Bin，CHEN Jiang
Institute of Quartz and Special Glasses,China Building Materials Academy
摘 要：The crystallization kinetics of 38.0CaO-38.0Al2O3-10.5BaO-6.5MgO-6.0Y2O3-1.0（Na2O+K2O）（wt%） glass was studied by differential scanning calorimeter（DSC） and X-ray diffraction（XRD） techniques.The results showed that DSC curves of calcium aluminate glass have a single glass transition temperature followed by one crystallization peak for the heating rates β=5 K/min and two crystallization temperatures Tp1 and Tp2 for β≥10 K/min.The activation energies of crystallization obtained from the Gao-Wang model of the first exothermal peak and the second exothermal peak of calcium aluminate glass are 340 and 662 kJ/mol,respectively.The Avrami exponents of the both crystallization peaks are approximately 2,indicating the twodimensional crystalline growth during its transformation from amorphous to crystalline.Ca12Al14O33,Ca3Al2O6 and unknown crystalline phases firstly appear when calcium aluminate glass is heat-treated.With the extending of heat-treatment duration,BaAl2O4 phase comes out.
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