• Journal of the Microelectronics and Packaging Society
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• v.31 no.2
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• pp.36-44
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• 2024

Copper electrodeposition technology is essential for producing copper films and interconnects in the microelectronics industries including semiconductor packaging, semiconductors and secondary battery, and there are extensive efforts to control the microstructure of these films and interconnects. In this study, we investigated the influence of crystallographic orientation on the local plastic deformation of copper films for secondary batteries deformed by uniaxial tensile load. Crystallographic orientation maps of two electrodeposited copper films with different textures were measured using an electron backscatter diffraction (EBSD) system and then used as initial conditions for crystal plasticity finite element analysis to predict the local plastic deformation behavior within the films during uniaxial tension deformation. Through these processes, the changes of the local plastic deformation behavior and texture of the films were traced according to the tensile strain, and the crystal orientations leading to the inhomogeneous plastic deformation were identified.

• Tunnel and Underground Space
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• v.16 no.2 s.61
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• pp.109-134
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• 2006

Rocks undergo weathering processes influenced by changing in pressure-temperature condition, atmosphere, underground water, and rainfall. The weathering processes change physical and chemical characteristics of the rocks. Once the rocks are weathered, the characteristics of them are changed and, because of the changing, several disadvantages such as rock slope failures and underground water spouts are can occur. Before we cut a large rock slope, therefore, we must analyze current weathering conditions of rocks and predict weathering processes in the future. Through the results of such analyses, we can judge reinforcement works. In order to comply with such requests, chemical weathering sensitivity analysis which was analyzed from chemical weathering velocities and other characteristics of rocks has been applied in several prior construction works in Korea. But, It is defective to use directly in engineering fields because it was developed for soils(not rocks), it has too mny factors must be considered and the relationships between the factors are not clear, and it is hard to explain the weathering processes in engineering time range. Besides above, because it has been used for isotropic rocks, this method is hard to apply to anisotropic rocks such as sedimentary rocks. Acceding to studies from morphologists (e.g. Oguchi et al., 1994; Sunamura, 1996; Norwick and Dexter, 2002), time dependent strength reduction influenced by weathering shows a negative exponential function form. Appling this relation, one can synthesize the factors which influence the weathering processes to the strength reduction, and get meaningful estimates in engineering viewpoint. We suggest this weathering sensitivity characterization method as a technique that can explain time dependent weathering sensitivity characteristics through strength changes and can directly applied the rock slope design.

• The Journal of Engineering Geology
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• v.34 no.3
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• pp.367-379
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• 2024

We analyzed the changes in the properties of the Mudeungsan tuff by conducting an artificial weathering experiment based on the climatic conditions of Mudeungsan National Park, to evaluate the long-term stability of the columnar jointing in the tuff. The climate of Mudeungsan National Park over 20 years suggests the temperature conditions for freeze-thaw are -20 to 30℃. The change in tuff properties due to weathering were estimated by measuring the elastic wave velocity, which was measured after every 40 freeze-thaw cycles. Based on the origin of the Mudeungsan tuff and fracture distribution in the tuff, the elastic wave velocity in samples from 24 locations was measured at regular intervals in the axial and radial directions. The axial elastic wave velocity of the Mudeungsan tuff is 5,187~5,367 m/s, and the radial elastic wave velocity is 4,001~5,290 m/s. As a result of 200 freeze-thaw cycles, the axial elastic wave velocity decreased by 5.53% for sample MT-1, 4.89% for MT-2, and 5.36% for MT-3. The radial elastic wave velocity decreased by 20.00% for MT-1, 17.02% for MT-2, and 19.84% for MT-3. The decrease in elastic wave velocity due to the freeze-thaw cycles is greater for low values of elastic wave velocity. For the axial elastic wave velocity, the weathering is accelerated after 120 cycles and, for the radial elastic wave velocity, weathering actively progresses from the start of the freeze-thaw cycles. In summary, for a low elastic wave velocity, experimental weathering results in a large decrease in elastic wave velocity. In addition, the Mudeungsan tuff and its columnar joints have a distinct anisotropy.