1999 Fiscal Year Final Research Report Summary
Non-Brittle Behavior of Inorganic Glasses
| Project/Area Number |
09450244
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | The University of Shiga Prefecture (1998-1999)
Kyoto University (1997) |
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Principal Investigator |
SOGA Naohiro Univ. Shiga Pref., School of Engineering, Professor, 工学部, 教授 (80026179)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Satoshi Univ.Shiga Pref., School of Engineering, Research Assistant, 工学部, 助手 (20275168)
MATSUOKA Jun Univ.Shiga Pref., School of Engineering, Assistant Professor, 工学部, 講師 (20238984)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Glass / Fracture / Slow Crack Growth / Oxycarbide Glass / Lithium Silieate / Activation Energy / Luminescence / Wallner Lines |
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| Research Abstract |
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.
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