• 한국안전학회지
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• 제24권1호
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• pp.1-6
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• 2009

In machining of ceramic materials, they are very difficult-to cut materials because of there high strength and hardness. Machining of ceramics are characterized by cracking and brittle fracture. Generally, ceramics are machined using conventional method such as grinding and polishing. However these processes are generally costly and have low MRR(material removal rate). This paper focuses on machinability evaluation of machinable ceramics for products with CNC machining center. Thus, in this paper, experiment applying cutting parameters is performed based on experimental design method. A design and analysis of experiments is conducted to study the effects of these parameters on the surface roughness by using the S/N ratio, analysis of ANOVA, and F-test. And multiple linear regression analysis is applied to compare experimental with predicted data in consideration of surface roughness. Cutting parameters, namely, feed, cutting speed and depth of cut are used to accomplish purpose of this paper. Required experiments are performed, and the results are investigated.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.597-602
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• 2002

Ceramics are very difficult-to-cut materials because of its high strength and hardness. Their machining mechanism is characterized by cracking and brittle fracture. In this paper, to give good machinability to the ceramics, BN powders are added to Si$_3$N$_4$ by volume of 20, 25 and 30%. And the machiniability of the produced ceramics are tested using micro drilling system. Through required experimental works, it is shown that the micro drilling machinability is varied along with the volumetric percentage of BN powders. Also, it is verified that the obtained results can be used to develop new machinable ceramics of good material properties and machinability.

• 한국공작기계학회논문집
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• 제12권6호
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• pp.36-43
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• 2003

In machining of ceramic materials, they are very difficult-to cut materials because of there high strength and hardness. Machining of ceramics are characterized by cracking and brittle fracture. Generally, ceramics are machined using conventional method such as finding and polishing. However these processes are generally costly and have low MRR(material removal rate). This paper focuses on determining the optimal levels of process parameters for products with CNC machining center. For this purpose, the optimization of cutting parameters is performed based on experimental design method. A design and analysis of experiments is conducted to study the effects of these parameters on the surface roughness by using the S/N ratio, analysis of ANOVA and F-test. Cutting parameters, namely, cutting speed, feed and depth of cut are optimized with consideration of the surface roughness.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.338-343
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• 2008

Fracture characteristics of plates and dome shapes for machinable glass ceramics using compressed shock wave. Machinable glass ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role separating solid and liquid fuel, and needs the frangible characteristics whereby the fracture of a part should not affect the internal components of combustion. The objective of this study are to evaluate the fracture pressure and phenomena of separated membrane using a shock tunnel. The experimental apparatus consists of driver, a driven section and a dump tank. The used material is machinable glass ceramic from Corning company. Specimens are used 3, 4.5 and 6mm thickness with plates and dome shapes. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.223-226
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• 2002

Appropriate design/manufacturing conditions, to give outstanding material properties to the $Si_3$$N_4$-BN and AIN-BN based composite materials, will be investigated using the experimental design methods. Ultra-precision machinability of the developed ceramics will be systematically studied in the viewpoint of microstructure and material properties. Also, finite element methods will be applied to define basic principles to significantly improve machinability and various properties. Basic experiments will be performed to develop optimum ultra-precision machining technologies for the developed ceramics. For ultra-precision lapping machining, need to develop a ultra-precision lapping system, suitable metal bonded diamond wheel, and appropriate condition of ultra-precision lapping machining.

• 한국세라믹학회지
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• 제48권5호
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• pp.348-353
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• 2011

By gel-casting, the silicon-polymer green bodies were prepared for silicon nitride ceramics, sintered by microwave gas phase reaction. Considering the viscosity and the idle time of slurries, we decided the operational conditions of related processes, and the optimum concentrations of raw materials powders, organic monomers, cross-linker, dispersant, initiator, and catalyst. So we could get the machinable green bodies, having about 50 MPa of bending strength without cracks by selecting drying conditions carefully.

• Journal of Electrical Engineering and information Science
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• 제3권1호
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• pp.68-72
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• 1998

The photomachinable glass-ceramics of Ag and CeO2 doped Li203-SiO2 (LAS)glass system was investigated as a function of UV irradiation time. After the expose and the non-exposed samples were heated, they went under crystalline phase with DTA, SEM, TEM and XRD of normal/high temperature. In this work, crystalline phases, microstructure and dielectric properties were studied under the various time of UV irradiation and heat treatment.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.123.2-123
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• 2003

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.102.2-102
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• 2002

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.117.2-117
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• 2003