• Ceramist
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• v.10 no.3
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• pp.15-27
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• 2007

Fabrication and electro-optic applications of glass optical fibers were reviewed. Theoretical description on the electro-optic Kerr effect in glass optical fibers, particularly for the second-order optical nonlinearity was given. Fabrication procedure and the characterization of the nonlinear electro-optic fibers with internal electrodes were described. Several electro-optic devices based on the polarimetric cells made by the nonlinear optical fibers with internal electrodes were also discussed with the experimental results on the electro-optic effect.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.129.1-129.1
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• 2005

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.628-633
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• 1998

단사정 HBO2 분막을 무기접착제로 이용하여 선택적 레이저 소결 기술을 적용시켜 알루미나-글래스 복합재료를 제조하였다. 만들어진 green SLS 시험편을 여러 온도에서 열처리하여 글래스-세라믹 복합재료를 얻었다. 글래스의 양이 많을수록 복합재료는 높은 밀도와 높은 굽힘강도를 보여주었다. 열처리 온도 $900^{\circ}C$에서 복합재료는 최대 밀도와 최대 강도를 나타낸다. 이것은 글래스의 낮은 점도로 인한 좋은 유동성 때문에 글래스의 재분배가 이루어졌기에 가능하다고 생각되어진다. 그리고 기공이 많은 열처리한 SLS 시험편에 콜로이드 실리카를 주입시켜 치밀화시켰다.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.99.2-99
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• 2003

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.190.1-190
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• 2003

• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.189-192
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• 1998

The mechanical properties of alkali resistance (AR) glass fiber reinforced cement(GFRC) under different curing conditions were investigated in this study. The specimens were formed by extrusion process, and then steam cured and autoclaved. An autoclaved specimen showed the elastic-brittle behavior up to 4% of fiber volume fraction. However, it was found that the fracture behavior for cured specimen was changed to the elastic-plastic with crack branches fracture at greater than 3 vol.% of fiber.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.149.2-149
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• 2003

• Korean Journal of Materials Research
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• v.33 no.7
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• pp.285-294
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• 2023

Porous ceramics are used in various industrial applications based on their physical properties, including isolation, storage, and thermal barrier properties. However, traditional manufacturing environments require additional steps to control artificial pores and limit deformities, because they rely on limited molding methods. To overcome this drawback, many studies have recently focused on fabricating porous structures using additive manufacturing techniques. In particular, the binder jet technology enables high porosity and various types of designs, and avoids the limitations of existing manufacturing processes. In this study, we investigated process optimization for manufacturing porous ceramic filters using the binder jet technology. In binder jet technology, the flowability of the powder used as the base material is an important factor, as well as compatibility with the binder in the process and for the final print. Flow agents and secondary binders were used to optimize the flowability and compatibility of the powders. In addition, the effects of the amount of added glass frit, and changes in sintering temperature on the microstructure, porosity and mechanical properties of the final printed product were investigated.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.1
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• pp.33-41
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• 1998

The response characteristics of the PZT transducers during glass capillary breakage were studied at the epicenter of the glass plate. The PZT transducers had been made by using EC-65 PZT ceramics(supplied by Edo co.) with a constant area and a various thickness. The theoretical displacement and velocity at the epicenter of glass plate with an air boundary condition were calculated by assuming the point load of 1N force strength and a rise time of 280 ns with a ramped functional dependence, and the 1st pulses of the PZT transducer may be considered as the vertical velocity incident on the electrode of the PZT ceramic. The responses of the PZT transducer may be depended on the thickness mode of the PZT ceramic below 0.33 in the ratio of the thickness to the diameter of PZT ceramic, but the reponse of the PZT transducer may be depended on the other modes of PZT transducer in the addition of the thickness mode of the PZT ceramic above 0.33. The full time of half maximum at the 1st pulse was nearly 280 ns without a variation of applied breakage load and the resonant frequency of the PZT transducer, and then may be considered as the rise time of a AE source. The maximum amplitude of the 1st pulse depended on the incident vertical velocity and capacitance of the PZT transducer. Therefore, the full time of half maximum and maximum amplitude of the 1st pulse may be considered as the rise time and strength of acoustic emission source respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.6
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• pp.277-281
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• 2009

Superhydrophobic $SiO_2$ thin films were successfully fabricated on a glass substrate by sol-gel method. To fabricate $SiO_2$ thin film with a high roughness, $SiO_2$ nano particles were added into tetraethoxysilane (TEOS) solution. The prepared $SiO_2$ thin film without an addition of $SiO_2$ nano particles showed a very flat surface with ca. 1.27 nm of root mean square (RMS) roughness. Otherwise, the $SiO_2$ thin films fabricated by using coating solutions added $SiO_2$ nano particles of 1.0, 2.0 and 3.0 wt% showed a RMS roughness of ca. 44.10 nm, ca. 69.58 nm, ca. 80.66 nm, respectively. To modify the surfaces of $SiO_2$ thin films to hydrophobic surface, a hydrophobic treatment was carried out using a fluoroalkyltrimethoxysilane (FAS). The $SiO_2$ thin films with a high rough surface were changed from hydrophilic to hydrophobic surface after the FAS treatment. Especially, the prepared $SiO_2$ thin film with a RMS roughness of 80.66 nm showed a water contact angle of $163^{\circ}$.