• Title/Summary/Keyword: Glass

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Fabrication of Metallic Glass/metallic Glass Composites by Spark Plasma Sintering (방전플라즈마 소결법에 의한 비정질/비정질 복합재의 제조)

  • Lee, Jin-Kyu
    • Journal of Powder Materials
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    • v.14 no.6
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    • pp.405-409
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    • 2007
  • The Cu-based bulk metallic glass (BMG) composites containing Zr-based metallic glass phase have been consolidated by spark plasma sintering using the mixture of Cu-based and Zr-based metallic glass powders in their overlapped supercooled liquid region. The Zr-based metallic glass phases are well distributed homogeneously in the Cu-based metallic glass matrix after consolidation process. The successful consolidation of BMG composites with dual amorphous phases was corresponding to the sound viscous flow of the two kinds of metallic glass powders in their overlapped supercooled liquid region.

Effects of Transition Temperature and Atomic Ratio on Glass Formation Tendency in the PbO-B$_2$O$_3$-TiO$_2$-BaO System (PbO-B$_2$O$_3$-TiO$_2$-BaO계의 유리화에 대한 전이온도 및 성분 원소비의 영향)

  • 이선우;심광보;오근호
    • Journal of the Korean Ceramic Society
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    • v.35 no.12
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    • pp.1274-1279
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    • 1998
  • The glass forming ability of the PbO-B2O3-TiO3-BaO system was investigated in relation to transitieon tem-peratures and the atomic ratio between constituents. Glass forming tendency was improved as the tem-peratures and the atomic ratio between constituents. Glass forming tendency was improved as the tem-perature differences between liquidus temperature and crystallization(or glass transition) temperature de-creased and the temperature difference between crystallization and glass transition temperature increases. The atomic ratio could be used as a criterion to deign glass systems. The interposition of B and Ba atoms between Pb and Ti atoms was one of important factors in glass formation.

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Glass Infilteration in Bonding of $BaTiO_3$ and $Al_2O_3$ Layers

  • Shin, Hyo-Soon;Wang, Jong-Hoe;Kim, Jong-Hee
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1209-1210
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    • 2006
  • A novel sintering process is proposed for bonding of $BaTiO_3$ and $Al_2O_3$ layers. Common commercial glass was used and infilterated among filler particles. As the kind of commercial glass, the phenomenon of the infilteration is different. Although Sud-1140 glass forms a glass/filler composite, it is not completely infilterated into the filler particles at $900^{\circ}C$. However as the increase of sintering temperature the infilteration of glass was improved. In this study, GA-1 and GA-12 glasses were infilterated the more than Sud-1140 glass. However, they are reacted by $BaTiO_3$ layer. The results of the experiment show that constrained sintering and the co-firing of the different materials were possible for glass infilteration using Sud-1140 glass at $1000^{\circ}C$.

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A sintering Behavior of Glass/Ceramic Composite used as substrate in High Frequency Range (고주파대역에서 기판으로 쓰이는 Glass/Ceramics Composite의 소결거동)

  • 이찬주;김형준;최성철
    • Journal of the Korean Ceramic Society
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    • v.37 no.4
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    • pp.302-307
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    • 2000
  • The objective of this study was to investigate the sintering behavior, crystallization characteristic of glass-ceramic and optimal sintering condition on the glass/ceramic composite for fabricating substrate of LTCC. Glass/ceramic composite was made from alumina powder and glass frit, which was composed of SiO2-TiO2-RO-PbO/(R: Ba, Sr, Ca), and was sintered for 0, 30, 60minutes in the temperature range from 700$^{\circ}C$ to 1000$^{\circ}C$. Properties of frit and glass/ceramic compsoite were analyzed by DTA, XRD, SEM and Network Analyzer and so on. Main sintering mechanism was densification occurred above 730$^{\circ}C$ by viscous flow and crystallization starting about 780$^{\circ}C$ affected sintering also. So viscous flow was affected by sintering temperature, duration time, and creation of crystallization phase etc. From this study, it was possible to fabricate glass/ceramic composite by changing sintering temperature and duration time.

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Glass Property Models, Constraints, and Formulation Approaches for Vitrification of High-Level Nuclear Wastes at the US Hanford Site

  • Kim, Dongsang
    • Journal of the Korean Ceramic Society
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    • v.52 no.2
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    • pp.92-102
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    • 2015
  • Current plans for legacy nuclear wastes stored in underground tanks at the U.S. Department of Energy's Hanford Site in Washington are that they will be separated into high-level waste and low-activity waste fractions that will be vitrified separately. Formulating optimized glass compositions that maximize the waste loading in glass is critical for successful and economical treatment and immobilization of these nuclear wastes. Glass property-composition models have been developed and applied to formulate glass compositions for various objectives for the past several decades. Property models with associated uncertainties combined with composition and property constraints have been used to develop preliminary glass formulation algorithms designed for vitrification process control and waste-form qualification at the planned waste vitrification plant. This paper provides an overview of the current status of glass property-composition models, constraints applicable to Hanford waste vitrification, and glass formulation approaches that have been developed for vitrification of hazardous and highly radioactive wastes stored at the Hanford Site.

A Study on the Strength of Mortar Substituted Fine Aggregate by Waste Glass Color (폐유리 색상별 잔골재를 치환한 모르타르의 강도에 관한 연구)

  • Jo, Su Yeon;Kim, Geon U;Shin, Joung Hyeon;Jung, Ui In;Kim, Bong Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.112-113
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    • 2021
  • Since natural sand is being depleted, research is being conducted to use glass similar to sand as an aggregate. When non-reusable waste glass is crushed and used as fine aggregate, it is known that alkali of cement and silica of glass react to cause an alkali aggregate reaction. The purpose of this study is to provide basic data by studying the strength according to color to use waste glass as fine aggregate. When 10% was replaced, both flexural and compressive strength showed strength values similar to those of Plain. When replaced by 20% and 30%, the 7-day intensity was higher than that of Plain. In addition, colorless glass was found to have the highest strength among glass colors. More research is expected to be needed to become a fine aggregate of waste glass.

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Energy Absorption Characteristics of the Al/CFRP/GFRP Hybrid Member under Quasi-static Axial Compressive Load (준정적 축 압축하중을 받는 Al/CFRP/GFRP 혼성부재의 에너지흡수 특성)

  • Kim, Sun-Kyu;Heo, Uk;Im, Kwang-Hee;Jung, Jong-An
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.4
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    • pp.588-592
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    • 2012
  • This study concentrates the effect of hybridisation on the collapse mode and energy absorption for composite cylinders. The static collapse behavior of laminated(Al/CFRP/GFRP) circular-cylindrical composite shell under quasi-static axial compressive load has been investigated experimentally. Eight different hybrids of laminated(Al/CFRP/GFRP) circular-cylindrical composite shell were fabricated by autoclave. Eight types of composites were tested, namely, Al/carbon fiber/epoxy, Al/glass fiber/epoxy, Al/carbon-carbon-glass/epoxy, Al/carbon-glass-carbon/epoxy, Al/carbon-glass-glass/epoxy, Al/glass-glass-carbon/epoxy, Al/glass-carbon-glass/epoxy and Al/glass-carbon-carbon/epoxy. Collpase modes were highly dominated by the effect of hybridisation. The results also showed that the hybrid member with material sequence of Al-glass-carbon-carbon/epoxy exhibited good energy absorption capability.

Forming Conditions of Curved Glass using Force Applying System of Glass Molding System (유리성형시스템의 힘측정기반 가압장치를 이용한 곡면유리 성형조건)

  • Hong, Tae Kyeong;Kim, Gab Soon
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.4
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    • pp.335-342
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    • 2014
  • This paper describes the forming conditions of smart-phone curved glass using the glass molding system with force applying system. The force applying system is composed of a body, a motor and gear, a rectilinear movement structure, a force sensor, a LVDT sensor (Linear Variable Differential Transformer), a up and down moving block, and so on. The glass molding system for characteristic test to find the forming conditions consists of the force applying system and a chamber, a metallic mold, a upper heater, a lower heater and so on. The characteristic test for forming conditions of smart-phone curved glass was carried out at forming temperature $620^{\circ}C$ and $650^{\circ}C$ using the glass molding system. As a result of the characteristic test, the forming conditions of curved glass could be found, and it is thought that the conditions can be used to apply to the system for producing in large quantities.

Histopathological Changes of Subcutaneous Exposure to Glass Fibers in Rats (흰쥐에서 유리섬유의 피하삽입에 의한 경시적 병리조직학적 변화)

  • Lee, Min-Jae;Cho, Soo-Hun;Jang, Ja-June
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.1 s.56
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    • pp.69-76
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    • 1997
  • To exanime in vivo tissue reactions of glass fibers, we injected glass fibers to rats subcutaneously. We made fibers of average dimensions of approximately $2{\mu}m$ in diameter and $60{\mu}m$ in length. After instilation of glass fiber we sacrificed rats sequentially at 1, 3 and 6 months. At 1 month after injection of glass fibers, the exposure area turned to yellow color and formed well-demarcated round mass. The average size of the mass was $1\times0.3cm$. Grossly detectable mass was decreased in size at 6 months compared to 1 or 3 months. Microscopically, strong foreign body reaction to glass fibers, inflammation and fibrosis were observed until 6 months. Foreign body reaction was increased up to 3 months, but it was decreased after 6 months. In scanning electron microscope, there was many bundles of glass fibers around the inflammation area, but the size of glass fibers were gradually reduced from 1 month to 6 months. These results suggest that subcutaneous exposure of glass fiber can provoke strong tissue reaction including foreign body granulomas, inflammation and fibrosis. But glass fiber itself did not produce any neoplastic changes.

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LCD Glass strain Simulation For Large Size Imprint Equipment (대면적 임프린트 장비를 위한 LCD Glass 변형 시뮬레이션 연구)

  • Song, Young-Joong;Shin, Dong-Hoon;Im, Hong-Jae;Jang, Si-Yeol;Lee, Kee-Sung;Jeong, Jay-Il
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1626-1631
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    • 2007
  • The purpose of the study is to simulate the displacement of the LCD glass during process of a large size imprint. During this process, a small temperature variation makes thermal stress, which causes the horizontal variation of mold and glass. During alignment process to fix the LCD glass on a alignment stage, the vertical displacement is made by the absorption pressure and the shear stress. This study simulates the horizontal displacement of mold and glass due to temperature variation, the vertical displacement depending on the shape of absorption surface fixing the LCD glass in the alignment process, and the horizontal and vertical displacement which occurs in the LCD glass at the alignment process. Algor which is a FEM code for a framework simulation was applied. Temperature variation above ${\pm}$ $0.1^{\circ}C$ on mold and glass causes the horizontal displacement of 150nm due to thermal expansion. The vertical displacement due to the circular is ten times of the case of rectangular absorption nozzle. The displacement of the LCD glass in the alignment process is about 49nm.

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