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Viscous flow mechanisms of fluoride glasses in wide temperature range.

氟化物玻璃在宽温度范围内的粘性流动机理。

基本信息

批准号：
63470056
负责人：
MATUSITA Kazumasa
金额：
$ 4.16万
依托单位：
Nagaoka University of Technology
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 1989
项目状态：
已结题

项目摘要

Fluoride glasses have attracted much attention because of infrared optical properties. The chemical bonds in fluoride glasses are much ionic compared with those in oxide glasses. Therefore, it is expected that many properties are different between fluoride glasses and oxideglasses. In the present study, the viscosity of fluoride glasses was measured in the wide temperature range.In the low temperature range, the viscosity in 10^6 - 10^<12> Pa・s was measured by the penetration method by using TMA (Thermomechnical Analyzer). In the limited range, the viscosity was found to be expressed by the Fulcher equation. The glass transition temperature. T_g, was determined by DSC and thermal expansion measurements as a function of the heating rate. The glass transition temperature at zero heating rate, T_<go>, was determined by exporatolation. It was found that the viscosity at T_<go> is always 10^<12>Pa・s irrespective of chemical composition of glass.For the measurement of high temperature viscosity, the rotational viscometer was constructed in which the atmosphere can be controlled. The vicosity in 10^<-1> - 10^2 Pa・s can be measured by this viscometer. It was found that at high temperature, the viscositu is very low and does not change with temperature so much whereas in the low temperature, the viscosity is very high and changes extraordinarily with temperature. The viscosity in the range between glass transition and 1200ﾟC cannot be expressed by a simple Fulcher equation and can be expressed by the Macedo-Litovitz equation, log eta = A + B/T + C/(T-To), with the assumption of B=BoT^<-2>.

氟化物玻璃因其红外光学特性而受到广泛关注。与氧化物玻璃相比，氟化物玻璃中的化学键更多地是离子键。因此，预计氟化物玻璃和氧化物玻璃之间的许多性质是不同的。本文在较宽的温度范围内测定了氟化物玻璃的粘度，在较低的温度范围内，<12>用TMA（Thermomechanical Analyzer）渗透法测定了氟化物玻璃的粘度（10^6 ~ 10^Pa·s）。在一定范围内，粘度可用Fulcher方程表示.玻璃化转变温度。用DSC和热膨胀法测定了玻璃化转变温度（Tg）与升温速率的关系。通过解析法测定了零升温速率下的玻璃化转变温度T_<go>。实验结果表明，玻璃的高温粘度<go><12>与玻璃的化学组成无关，均在10^ Pa·s左右。该<-1>粘度计可测量10^ - 10^2 Pa·s范围内的粘度。结果表明，在高温下，粘度很低，随温度变化不大，而在低温下，粘度很高，随温度变化很大。在玻璃化转变和1200 ℃之间的范围内的粘度不能用简单的Fulcher方程表示，并且可以用Macedo-Litovitz方程表示，log eta = A + B/T + C/（T-To），假设B=BoT^<-2>。