Modeling nonisothermal crystallization in a BaO∙2SiO 2 glass
Modeling nonisothermal crystallization in a BaO∙2SiO 2 glass
复制标题
BaO–2SiO 2 玻璃中的非等温结晶建模
DOI：
10.1111/jace.16979
复制
发表时间：
2020
影响因子：
3.9
通讯作者：
Kelton, K. F.
中科院分区：
文献类型：
--
作者：
Van Hoesen, D. C.;Xia, Xinsheng;McKenzie, Matthew E.;Kelton, K. F.
差热分析（DTA）技术预测显着成核的温度范围内的准确性，检查在一个BaO_2SiO_2玻璃迭代数值计算。数值模型考虑了时间相关的成核、有限的颗粒尺寸、尺寸相关的晶体生长速率和表面结晶。的计算是使用经典的，并首次，扩散界面理论的成核。计算结果与实验测量结果一致，证明了DTA技术的有效性。他们表明，这是独立的DTA扫描速率使用和表面结晶有一个可以忽略不计的影响的玻璃粒度研究。粘度和扩散系数之间的Stokes-Einstein关系的故障被证明为低温，接近最大成核速率。然而，它表明，准确的扩散系数的值可以从成核的诱导时间和在此温度范围内的生长速度。
The accuracy of a differential thermal analysis (DTA) technique for predicting the temperature range of significant nucleation is examined in a BaO∙2SiO2glass by iterative numerical calculations. The numerical model takes account of time‐dependent nucleation, finite particle size, size‐dependent crystal growth rates, and surface crystallization. The calculations were made using the classical and, for the first time, the diffuse interface theories of nucleation. The results of the calculations are in agreement with experimental measurements, demonstrating the validity of the DTA technique. They show that this is independent of the DTA scan rate used and that surface crystallization has a negligible effect for the glass particle sizes studied. A breakdown of the Stokes‐Einstein relation between viscosity and the diffusion coefficient is demonstrated for low temperatures, near the maximum nucleation rate. However, it is shown that accurate values for the diffusion coefficient can be obtained from the induction time for nucleation and the growth velocity in this temperature range.