• Korean Journal of Materials Research
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• v.11 no.7
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• pp.545-549
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• 2001

Glass-ceramics were prepared and evaluated for the properties to expand the scope of application of the rare earth aluminosilicate glasses, A glass-ceramic added with $TiO_2$as a nucleating agent, which was crystallized internally and it was characterized for physical, thermal and mechanical properties of crystal and residual glass in the glass-ceramic, X-ray diffractometer reveals an unknown crystal as $Nd_{4.6}Si_{7.6}Al_{4.0}Ti_{2.4}O_{32}$ which was found in surface and internal crystals dependent on composition and heat treatments. The thermal expansion coefficients of glass-ceramics were $5.4~6.2{\times}10^{-6}/^{\circ}C$, which increased with increasing crystal growth. Considering that the hardness and the elastic constant of crystal in glass-ceramics are 12GPa and 220GPa, respectively, the application of the glass-ceramics would be applicable for structural materials at elevated temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.91-94
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• 2001

Glass ceramics composed of (5-X)$Li_2O$ㆍ$XAg_2O$ㆍ36CaOㆍ$20TiO_2$.27$P_2O_5$(X=1 to 5) were prepared by melting process and 2 step heat treatment for nucleation at$610^{\circ}C$ and crystallization at $730^{\circ}C$, Fabricated crystal phases were $LiTi_2(PO_4)_3$(LTP),$AgTi_2(PO_4)_3$(AgTP)와 $\beta-Ca_3(PO_4)$. Antibacterial effects and characterizations of the glass ceramics as $Ag_2$O content were investigated. Staphylococcus aureus and Salmonella typhi were used in this study. Staphylococcus aureus and Salmonella typhi bacteria were removed 5 hours added after glass ceramics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.291-294
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• 2000

The crystallization behavior and dc Conductivities of CuO-P$_2$O$_{5}$ -Nb$_2$O$_{5}$ -V$_2$O$_{5}$ glasses prepared by quenching on the copper plate were investigated. The conductivities of the glasses were range from 10$^{-5}$ s.$cm^{-1}$ / at room temperature, but the conductivities of the glass-ceramics were 10$^{-3}$ s.$cm^{-1}$ / increased by 10$^2$order. The crystalline product in the glass-ceramics was CuV$_2$O$_{6}$ . The linear relationship between in($\sigma$T) and T$^{-1}$ suggested that the electrical conduction in the present glass-ceramics would be due to a small polaron hopping mechanism.

• Journal of the Korean Ceramic Society
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• v.29 no.3
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• pp.223-231
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• 1992

CaO and ZnO were added to Al2O3-SiO2 binary system respectively as flux, then ZrO2 and TiO2 were applied as nucleating agent to these CaO-Al2O3-SiO2 and ZnO-Al2O3-SiO2 ternary system glass. The transparency could not be kept in CaO-Al2O3-SiO2 system glass, whereas the transparent glass-ceramics were prepared in ZnO-Al2O3-SiO2 system glass containing ZrO2 as the nucleating agent. At this time the optimum heating temperatures for the nucleation and the crystal growth were 78$0^{\circ}C$ and 97$0^{\circ}C$. The sizes of the precipitated crystals in the transparent glass-ceramics were below 0.1 ${\mu}{\textrm}{m}$, and their light transmissibilities were more than 80%.

• Resources Recycling
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• v.13 no.1
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• pp.54-58
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• 2004

Wollastonite-type glass ceramics were prepared by milling and firing at various temperatures using an automobile waste glass and waste shell as starting materials. Powder mixture ground by disk-type ball mill for 3 hours was pressed into a disk. The pressed specimen was fired at $850^{\circ}C$,$950^{\circ}C$ and $1050^{\circ}C$ for 1 hour in air. From FE-SEM observation, with an increase of the firing temperature from $850^{\circ}C$ to $1050^{\circ}C$, whisker-type phase was grown to about 10 $\mu\textrm{m}$ in length. Specimen fired at $1050^{\circ}C$ showed the formation of well-crystallized whisker-type wollastonite grains and the highest compressive strength.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.249-250
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• 2006

Recently FPD(Flat Panel Display) is used in various field to display enormous information. So cutting technique of flat panel display is needed for producing variety display merchandises. In present, cutting methods of flat panel glass includes breaking process. But this process occurs many glass particles. This glass particles are directly related badness of merchandise and falling productivity. In this paper, to cut front substrate glass of LCD and to get optimized cutting condition are tried fur eliminating breaking process with developed glass cutting machine using a Piezoelectric ceramics actuator. It is known that the vibration of Piezoelectric Ceramic have effect in crack proceeding through the analysis of fracture section.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1218-1219
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• 2006

The shrinkage variation of Low Temperature Cofired Ceramics(LTCC) limits the size of the substrates that impose limitations on embedded passive components. This paper focuses on the method of minimizing or controlling planar shrinkage and reducing distortion during firing. The laminated sheets of alumina and glass were sintered at varying temperature, and depending on the amount of the glass ceramics. When the sintered of multi-layer structure with $Al_2O_3/Glass/Al_2O_3$, the glass infiltrated entirely into $Al_2O_3$ layer at the temperature of about $950^{\circ}C$ or higher.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.20-20
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• 1997

• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1337-1345
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• 1994

Glasses in the system of 45CaO-25TiO2-30P2O5 containing 1 mole% of M2O(M=Li, Na, K) were melted and crystallized. And their crystal phases were Ca3(PO4)2, CaTi4(PO4)6, and TiO2. Porous glass-ceramics with skeleton of two crystal phase CaTi4(PO4)6 and TiO2 were prepared by selective leaching of Ca3(PO4)2 with 0.1 N-HCl. Glass transition temperature(Tg) and crystallization temperature(Tc) were decreased by addition of 1 mole% alkali metal oxide. Pore size of porous glass-ceramics was increased with increasing heat treatment temperature and its dependence on heat treatment temperature was decreased with addition of Na2O and K2O. It was found that porous glass-ceramics of parent glass and containing 1mole% M2O(M=Li, Na, K) composition had maximum specific surface area, porosity and maximum of crystallzed phase by heat treatment at 80$0^{\circ}C$, 76$0^{\circ}C$, 78$0^{\circ}C$, 80$0^{\circ}C$ respectively.

• Korean Journal of Materials Research
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• v.26 no.5
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• pp.266-270
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• 2016

Glass-ceramics were developed many years ago and have been applied in many fields such as electronics, chemistry, optics, etc. Much is already known about glass-ceramic technology, but many challenges in glass-ceramic research are still unresolved. Recently, large amounts of slag have steadily increased in the steel industry as by-products. To promote recycling of industrial waste, including steel industry slags, many studies have been performed on the fabrication of basalt-based high-strength glass-ceramics. In this study, we have fabricated such ceramics using various slags to replace high performance cast-basalt, which is currently imported. Glass-ceramic material was prepared in similar chemical compositions with commercial cast-basalt through a pyro process using slags and power plant by-product (Fe-Ni slag, converter slag, dephosphorization slag, Fly ash). The properties of the glass-ceramic material were characterized using DTA, XRD, and FE-SEM; measurements of compressive strength, Vicker's hardness, and abrasion were carefully performed. It is found that the prepared glass-ceramic material showed better performance than that of commercial cast-basalt.