基于有限元法模拟微晶玻璃的微晶化加热过程

摘要

The CaO-Al2O3-SiO2 (CAS) glasses that were prepared by natural cooling yellow phosphorus furnace slag were taken as research objects.On the basis of ANSYS finite element analysis,the numerical simulation of the crystallization behavior process of glass-ceramics was carried out to obtain the curve equation of the center point and the end point temperature field of the glass changing with time.The results show that the variation of center temperature and the endpoint temperature value of internal glass with time have a high fitting degree with the exponential equation in the stage of heating from room temperature to nucleation temperature (25-780 ℃) and from the nucleation temperature to crystallization temperature (780-1 080 ℃).In order to prevent the large temperature gradient distribution and thermal stress generation in the heating process of the crystallization behavior process of glass-ceramics,the heating rate should be controlled at 2-4 ℃/min in the stage of 25-780 ℃ and at 0-2 ℃/min in the stage of 780-1 080 ℃ respectively.Through differential thermal analysis and X-ray diffraction,the glass specimen were heated to nucleation temperature (780 ℃) at 3 ℃/min,and then heated to crystallization temperature (1 080 ℃) at 1 ℃/min to obtain the CaO-Al2O3-SiO2 microcrystalline glass,which was then verified by experiment to obtain the glass-ceramics with excellent property whose main crystalline phase were wollastonite (CaSiO3),containing wollastonite type of solid solution of iron ((Ca,Fe)SiO3).%以CaO-Al2O3-SiO2系基础玻璃为研究对象,基于ANSYS有限元分析对基础玻璃微晶化过程进行了数值模拟,得到了基础玻璃内部中心点和端点温度场随时间的变化曲线方程.结果显示,在从室温加热到核化温度阶段(25～780℃)和从核化温度加热到晶化温度阶段(780～1 080℃),基础玻璃内部的中心点温度和端点温度值随时间变化与指数方程拟合度较高.为防止在加热过程中温度场中有较大的温度梯度分布和热应力的产生,在25～780℃阶段的升温速率应控制在2～4℃/min;在780～1 080℃阶段的升温速率应控制在0～2℃/min.通过差热分析和X射线衍射等分析手段对以3℃/min的升温速率升至核化温度(780℃)后又以1℃/min的升温速率升至晶化温度(1 080℃)后制得的CaO-Al2O3-SiO2系微晶玻璃进行了实验验证,得到了主晶相为硅灰石(CaSiO3)和含铁硅灰石类固溶体((Ca,Fe)SiO3)且性能优异的微晶玻璃.