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Vol.45, No.5, 285 ~ 292, 2007
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| Title |
| In-situ Monitoring of Catastrophic Fracture Behavior in MgO Stabilized ZrO2 by using M-L Paint. |
| 김지식 Ji Sik Kim , 손기선 Kee Sun Sohn , 고향진 Hyang Jin Koh , 이완두 Wan Boo Lee |
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| Abstract |
| The recently devlopoped ML(Mechano-Luminescence) technique enables macro-scale visualization of crack propagation during catastrophic failure, together with transformation zone (crack wake) in both crack front and side areas of Mg-PSZ in realistic time frame. The ML made it possible to precisely detect a relatively fast crack propagating in the speed range from 5 to 15 m/sec, thereby realizing so-called quasi-dynamic R-curve. A systematic observation of growth in wake height, as well as wake length, was made successfully in quasi-dynamic condition. Effective-toughening applied-stress intensity factor increased up to 22 MPa(m)(1/2). The h0 values obtained from the ML observation deviated significantly from that predicted by Evans-McMeeking model(J. Am. Ceram. Soc. 65,242(1982)); rahter it supports Marshall et al.`s results by interference microscopy and Raman spectroscopy (J Am. Ceram. Soc. 73,2659(1990)) in the quasi-static crack propagation. It was also mentioned that conventional R-curves spanning over several millimeters range reported for long-crack systems such as DCB(Double Cantilever Beam), CT(Compact Tension), SENB(Single Edged Notched Bar), and etc. can not be explained by Evans-McMeeking model. |
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| Key Words |
| Mechano-Luminescence, M-L, Paint, Crack Propagation, Transformation (Crack Wake) Zone, Mg-PSZ |
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