• Transactions of Materials Processing
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• v.33 no.5
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• pp.363-370
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• 2024

This study investigated the evolution behavior of microtexture developed in Ta-10W alloy during cold rolling. The changes in microtexture during the cold rolling process were experimentally analyzed using EBSD techniques. At relatively low rolling reductions (20%, 40%), θ-fiber and α-fiber textures were developed. However, as the reduction increased to 60% and 80%, strong α-fiber and γ-fiber textures were observed. The microtexture behavior was theoretically predicted using the VPSC polycrystal model under plane strain compression(PSC) and conditions considering deformation in the transverse direction. The VPSC model results under PSC predicted the strong development of θ-fiber texture at low reductions (20%, 40%) and the development of α-fiber and γ-fiber textures as the reduction increased to 60% and 80%. The VPSC model considering transverse deformation predicted results similar to the plane strain PSC at low reductions (20%, 40%), but as the reduction increased to 60% and 80%, it predicted that the development of α-fiber texture would be relatively weak, and the θ-fiber texture would still remain even at an 80% reduction. It was confirmed that the VPSC model considering transverse deformation more accurately predicts the evolution behavior of microtexture observed experimentally.

• Laser Solutions
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• v.15 no.3
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• pp.11-15
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• 2012

The laser weld of AZ31 magnesium alloy was characterized with OM, EBSD and micros vickers hardness tester in experiment. EBSD analysis and micro-hardness measurements were carried out at the three regions (Equiaxed Zone, Columnar Dendrite Zone, Base Metal) of the welded AZ31Mg alloy sheets. The magnesium alloy show the rectangular shape bead in laser weld. EBSD analysis revealed that the three regions show the heterogeneous distribution of grain size and microtexture. Micro-hardness measurement also revealed that the heterogeneous distribution of microstructure contributed to the heterogeneous micro-hardness distribution in the three regions.

• Journal of Welding and Joining
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• v.28 no.5
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• pp.20-27
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• 2010

• The Journal of Engineering Geology
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• v.21 no.4
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• pp.381-391
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• 2011

Weathering can reduce rock strength and eventually affect the structural stability of a rock mass, which is important in the field of engineering geology. Several methods have been developed to evaluate the degree of weathering, including the chemical weathering index. In this study, we analyzed the weathering degree and characteristics of microtextures and pores in crystalline rocks (gneiss and granites) based on petrographic observations, the chemical weathering index, mineralogy by XRD, microtextural analysis by SEM/EDS, measurements of pore size and surface area by the BET method, and microporosity by X-ray CT. The formation of secondary minerals and microtexture in gneiss and granitic rocks are assumed to be affected by complex processes such as dissolution, precipitation, and fracturing. Hence, it is clear that some chemical weathering indices that are based solely on whole-rock chemistry (e.g., CIA and CWI) are unable to provide reliable assessments of the degree of weathering. Great care is needed to evaluate the degree of chemical weathering, including an understanding of the mineralogy and microtexture of the rock mass, as well as the characteristics of micropores.

• The Korean Journal of Ceramics
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• v.3 no.2
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• pp.129-133
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• 1997

Fine powder of $\alpha$-tricalcium phosphate, tetracalcium phosphate and dicalcium phosphate were mixed together to prepare self-setting cements which form hydroxyapatite, one of the well-known biocompatible materials, as the end of products of hydration. Hardening behaviour of the cements was examined at the temperature range of 37~$70^{\circ}C$ and 150~$250^{\circ}C$ under the normal and hydrothermal condition respectively. The conversion of cements into hydroxyapatite was significantly improved ast elevated temperature and the paste was strengtheed by interlocking of hydroxyapatite crystals, indicating that the strength is determined by microtexture rather the amount of conversion of cements into hydroxyapatite.

• 보존과학연구
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• s.26
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• pp.27-40
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• 2005

This study is to be investigated through component analysis and metallurgical texture in order to save an information of the manufacturing technique for the bronze bell in Naksan-sa. The bronze bell was analyzed with nine samples not stirred by the fire and except the contents of tin is the maximum and minimum the average of Cu is 81.8wt%, Sn is15.8wt% and indicates that some impurities are in it. With the result of an analysis of component and microtexture for impurities material which exists in it with using the SEM-EDS, the material was revealed the sulfur. As the result of these factors, the bronze bell of Naksan-sa is used from ore which mainly consist of the Chalcopyrite($CuFeS_2$) or Bornite($Cu_5FeS_4$) containing much sulfur.

• 보존과학연구
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• s.31
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• pp.141-154
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• 2010

Many bronze artifacts have been excavated and preserved through conservation treatments in Korea but the analysis on artifacts was regarded as destruction of artifacts from the academic world of archaeology, Therefore, it is not so available to perform research on production techniques and provenances by with qualified analysis. Accordingly, there were only a few study cases about quality properties and production techniques But recently gradual change started to appear from the awareness of the need for the scientific approach to excavated artifacts. While Korean ancestors already had applied the different alloying ratios according to the use and shape of bronze artifacts, the analysis and study have been restrictedly performed. As a result, there was only a few analysis cases on a small minority of artifacts because they are the ancient relics, which made it hard to understand the bronze artifacts more deeply. This study researched into components rate, production techniques and hardness of bronze weapons such as a bronze sword and compared their alloying ratios with those of Chinese old records (周禮考工記, 金之六齊).

• Journal of the Korean Ceramic Society
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• v.34 no.11
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• pp.1151-1158
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• 1997

Fracture of uni-directional carbon fiber reinforced carbon matrix composite is strongly dependent on the orientation of basal plane in graphite matrix when it is limited within matrix. The orientation of basal planes are vertically stacked to carbon fiber which results in the weakness for applied tensile or shear force in thermosetting resin derived-carbon matrix composite. Microtextural control of the matrix was tried through chemical interaction between metal carbides and furan resin derived-carbon matrix. SiC and TiO2 addition made the orientation disordered. However, porosity increased due to decomposition of SiC. Interfacial bonding could be controlled by TiO2 addition, but carbon fiber was considerably reacted with TiC during thermal treatment higher than 2$600^{\circ}C$. Therefore, it is desirable to control the thermal treatment temperature at which decomposition of SiC was not serious and TiC/C was not formed eutectoid.

• Journal of the Korean Society of Visualization
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• v.22 no.2
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• pp.82-89
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• 2024

In this study, experiments were conducted to visualize and analyze the dynamic characteristics of splash and residual liquid film formation during and after the injection of water droplets onto vertically situated solid substrates with varying surface wettability, elasticity, and microtexture. As wettability decreased (higher contact angle), more splash droplets formed, and the residual liquid film decreased. Low contact angles resulted in thin residual films and less splash. Surface elasticity absorbed the impact forces of droplets, thereby decreasing splash phenomena and significantly reducing the formation of residual liquid films due to surface vibration. Surfaces with microtextures demonstrated control over droplet splash direction, guiding the liquid along desired pathways. High-speed imaging provided detailed insights, showing that surface properties critically influence splash dynamics and residual liquid film formation.

• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.447-462
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• 2005

The purposes of this study are to evaluate and discuss the importance of geochemical properties of soil materials that play an important role in the occurrence of the landslide, using analyses of microtexture, particle size distribution, XRC, and FE-SEM equipped with energy dispersive spectrum on soils collected from landslide slopes of gneiss, granite and sedimentary rock areas. Soils from gneiss and granite areas where landslides took place have much clay content relative to those from non landslide areas, particularly pronounced in the granite area. Therefore the clay content is considered a sensitive factor on landslide. Clay minerals contained in soils are illite, chlorite, kaolinite and montmorillonite. Especially the content of clay minerals in soils from the Tertiary sedimentary rocks is highest, with abundant montmorillonite as expandable species. It is believed that this area was much vulnerable to landslide comparable to other areas because of its high content of monoorillonite, even though there might be weak precipitation. Since no conspicuous differentiation in mineralogy between the landslide area and non landslide area can be made, the occurrence of landslide may be influenced not by mineralogy, but by local geography and mechanical properties of soils. Geochemical information on weathering properties, mineralogy, and microtexture of soils is helpful to better understand the causes and patterns of landslide, together with engineering geological analyses.