A MOLECULAR INTERPRETATION OF STRESS-CORROSION IN SILICA
A MOLECULAR INTERPRETATION OF STRESS-CORROSION IN SILICA
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DOI：
10.1038/295511a0
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发表时间：
1982-01-01
期刊：
影响因子：
64.8
通讯作者：
FREIMAN, SW
中科院分区：
文献类型：
--
作者：
MICHALSKE, TA;FREIMAN, SW
在静载荷和环境下，许多玻璃和陶瓷材料的机械强度随着时间的推移而降低。由于应力腐蚀过程，这种强度损失与先前存在的表面缺陷的缓慢增长有关。为了对陶瓷构件进行长期强度预测，了解应力腐蚀机理是十分重要的。我们已经研究了暴露于水和几种非水环境中的玻璃二氧化硅的应力腐蚀，并在这里报告了增强应力腐蚀的环境是由一端有电子给体位点和另一端有质子给体位点的分子群组成的。这些结果提出了一个详细的化学模型，用于环境与裂纹尖端固体中的机械应变键的相互作用。所提出的模型对各种脆性材料的长期强度行为也有影响。
The mechanical strength of many glasses and ceramic materials decreases with time under static loading and ambient environments. This strength loss is associated with slow growth of pre-existing surface flaws due to a stress-corrosion process. To make long-term strength predictions for ceramic components, it is important to understand the stress-corrosion mechanism. We have studied stress corrosion in vitreous silica exposed to water and several non-aqueous environments and report here that environments which enhance stress corrosion are composed of molecular groups with electron donor sites on one end and proton donor sites at the other. These results suggest a detailed chemical model for the interaction of the environment with mechanically strained bonds in the solid at the tip of a crack. The proposed model also has implications for the long-term strength behaviour of a wide variety of brittle materials.