Non-Brittle Behavior of Inorganic Glasses

无机玻璃的非脆性行为的存在还没有得到广泛的研究，但从压痕断裂分析和静态表面能的比较，这将是常见的。因此，作为普遍接受的方法来评估的顺序的非脆性，许多方法进行了审查，在这项研究中。结果表明：在水分子存在下，硼酸盐玻璃的裂纹缓慢扩展行为与硅酸盐玻璃不同，在断裂时表现出较大的非弹性变形，在硼酸盐玻璃中，在具有非常低的应力强度因子的区域观察到应力无关的裂纹扩展。在惰性条件下，即，本文用新近发展的应力波断裂学慢裂纹扩展的DCDC测量方法，测量了二硅酸锂和钠钙硅酸盐玻璃在不同温度下的本征慢裂纹扩展。在相同裂纹扩展速率下，锂二硅酸盐玻璃的应力强度因子大于钠钙硅酸盐玻璃。前者的裂纹缓慢扩展激活能远小于后者。在前者中，在150℃以上观察到非阿氏温度依赖性。在稀土掺杂的六方晶系晶体中观察到可见光区的断裂诱导发光。这一现象的起因应是六方铈矿在紫外区的断裂发光激发了稀土离子。

Existence of the non-brittle behavior of inorganic glass has not been studied widely though it will be common from the analysis of indentation-fracture and the comparison between fracture and static surface energies. So, as the commonly accepted method to evaluate the order of non-brittleness, many approaches are examined in this study. Results are as follows :In the existence of water molecules, slow crack growth behavior of borate glasses which shows large inelastic deformation at fracture is found to be different from that of silicate glasses, I.e., stress-independent crack propagation is observed in borate glasses at a region with very low stress intensity factor.Slow crack growth behavior at inert condition, I.e., intrinsic slow crack growth, with various temperatures is measured for lithium disilicate and soda lime silicate glasses using a newly developed DCDC measurement of slow crack growth with stress-wave fractography. The stress intensity factor with the same crack growth rate of the lithium disilicate glass is found to be larger than that of soda lime silicate. The activation energy of slow crack growth for the former glass is much smaller than that of latter one. In the former glass, non-Arrhenius temperature dependence is observer above 150℃.Fracture-induced luminescence in the visible region is observed in rare-earth doped hexacelsian crystals. The origin of this phenomenon should be fractoluminescence of hexacelsian in the UV region that would excite the rare-earth ions.