Temperature-dependent densification of sodium borosilicate glass
Temperature-dependent densification of sodium borosilicate glass
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硼硅酸钠玻璃的温度依赖性致密化
DOI：
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发表时间：
2015
期刊：
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通讯作者：
Morten M. Smedskjær
中科院分区：
文献类型：
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作者：
M. B. Østergaard;R. Youngman;M. N. Svenson;S. Rzoska;M. Boćkowski;L. Jensen;Morten M. Smedskjær
从高压状态回收的致密玻璃由于其物理和化学性质的改变而具有潜在的技术兴趣。在这里，我们研究了1 Gpa气压下，钠硼硅酸盐玻璃的致密化行为随温度的变化。温度在0.6Tg到1.15Tg之间变化，其中Tg是玻璃化转变温度，对于0.9Tg的压缩，处理时间在10到10 000min之间变化。当温度高于0.7Tg时，发生永久致密化，致密化程度随着压缩温度和时间的增加而增加，直到超过Tg的温度达到大致恒定值。玻璃的力学性能(硬度和脆性)和网络结构(即三配位与四配位的硼原子和环与非环的三角硼原子的比例)以及Si和B的混合程度与温度和时间的关系也是相同的。这一结果为深入了解网络致密化的温度依赖性以及粘性流动和更局域重排的相对作用提供了深入的见解。
Densified glasses recovered from a high-pressure state are of potential technological interest due to their modified physical and chemical properties. Here we investigate the temperature-dependent densification behavior of a sodium borosilicate glass in a gas pressure chamber at 1 GPa. The temperature is varied for a 30 min treatment between 0.6Tg and 1.15Tg, where Tg is the glass transition temperature, and the treatment duration is varied between 10 and 10 000 min for compression at 0.9Tg. Permanent densification occurs for temperatures above 0.7Tg and the degree of densification increases with increasing compression temperature and time, until attaining an approximately constant value for temperatures above Tg. The same temperature and time dependence is also found for the glass mechanical properties (hardness and brittleness) and the network structure, i.e., fraction of three-fold versus four-fold coordinated boron atoms and ring versus non-ring trigonal boron atoms, and the extent of mixing of Si and B. The results provide insights into the temperature-dependence of the network densification and the relative roles of viscous flow and more localized rearrangements.