冷却-加热对CaO-Al2O3-SiO2系玻璃析晶动力学的影响

以CaO-Al2O3-SiO2系玻璃为研究对象,采用Ozawa方程、Kissinger方程和JMA修正方程研究了冷却方式和加热温度对玻璃析晶动力学的影响。结果表明:化学组成相同的玻璃,冷却速度和加热温度对其析晶活化能E、Avrami指数n和析晶速率指前因子ν都有影响,但加热温度对析晶活化能E的影响更大,并在750℃出现极大值现象。通过玻璃析晶试验发现:冷却速度和加热温度对微晶玻璃主次晶相的析出没有影响,主、次晶相分别是钙长石和榍石。冷却速度和加热温度对析晶活化能E的影响主要来源于析出主、次晶相的比例不同。

Effect of cooling-heating on crystallization kinetics of CaO-Al2O3-SiO2system glass

Effect of cooling method and heating temperature on transformation kinetics of CaO-Al2O3-SiO2 system glass was studied using Ozawa equation,Kissinger equation and the correctional equation JMA.The results show that for the glass with the same chemical composition,the activation energy of crystallization E,Avrami exponent(n) and the pre-exponential factor of crystallization rate(ν) are influenced by the cooling velocity and heating temperature,moreover the activation energy of crystallization E is significantly affected by heating temperature,the maximum activation energy of crystallization E appears at 750 ℃.The experiment of glass crystallization shows that the primary and secondary crystal phase of glass ceramics is not influenced by the cooling velocity and heating temperature,primary and secondary crystal phases of glass ceramics are anorthite and titanite,respectively.The effect of cooling velocity and heating temperature on the crystallization activation energy exists because of the different proportion of the primary and secondary crystal phase precipitated.