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Studies on the Change of Physical Properties of Glassy Slags Near Glass Transition. Region.

玻璃渣近玻璃化转变物理性质变化的研究。

基本信息

批准号：
63470048
负责人：
SHIRAISHI Yutaka
金额：
$ 4.54万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

In order to apply a glass transition behavior to an estimation of the properties at higher temperatures, the followings were carried out : 1. Viscosity measurement over a wide temperature range, 2. Devitrification of glass solder after joining of cermics by a suitable heat treatment in which the temperatures were determined by glass transition and crystallization temperatures, 3. Molecular dynamic simulation for shear viscosity of molten silicates. Obtained results are summarized as follows :1. The viscosity of borosilicate and oxynitride systems were measured by a parallel plate viscometer (measuring range 10^<10> - 10^5 poise) and a rotating crucible viscometer (10^3 - 10^0 poise). The viscosity range corresponds to the temperatures from 700 - 1600 ^0C, i. e. from glassy to molten states. Mechanism of viscous flow is quite different but Fulcher funtion could be applied well to interpolate the viscosity in the mid range of both states. However, it can not be found the correlation between Tg and Fulcher constant To.2. MgO- and CaO-Al_2O_3-SiO_2 system containing nucreating reagent were used as a glass solder for joining of ceramics. Measured Tg and Tc were used to determined the heat treatment temperatures at which nucreation and crystal growth proceed. After devitrification of solder glass, higher strength of joining were achieved, more than 200 MPa.3. Molecular dynamic simulation was applied to a viscosity calculation of molten sodium silicate system. Qualitative reproduction were obtained both for temperature and compositional dependence of viscosity. However, it seems to be very hard to reproduce a quantitative result for the transport behavior of such a highly networked systems owing the limitation of capacity of caculater nowadays.

为了将玻璃化转变行为应用于在较高温度下的性质的估计，进行了以下工作：1.在宽温度范围内进行粘度测量，2.通过适当的热处理，其中温度由玻璃化转变温度和结晶温度决定，3。硅酸盐熔体剪切粘度的分子动力学模拟。主要研究结果如下：1.硼硅酸盐和氮氧化物体系的粘度通过平行板粘度计（测量范围为10^<10>- 10^5泊）和旋转坩埚粘度计（10^3 - 10^0泊）测量。粘度范围对应于700 - 1600 ° C的温度，i. e.从玻璃态到熔融态粘性流动的机理是完全不同的，但Fulcher函数可以很好地应用于插值的粘度在中间范围内的两个状态。但是，没有发现Tg与Fulcher常数To之间的相关性.本文采用MgO-和CaO-Al_2 O_3-SiO_2系玻璃作为陶瓷连接的玻璃焊料。测量的Tg和Tc用于确定成核和晶体生长进行的热处理温度。焊料玻璃失透后，接头强度达到200 MPa以上.将分子动力学模拟应用于硅酸钠熔融体系粘度的计算。定性再现得到的温度和组成依赖性的粘度。然而，由于目前计算器容量的限制，对于这样一个高度网络化的系统的传输行为似乎很难再现一个定量的结果。