• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 추계학술대회 논문요약집
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• pp.64-64
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• 2003

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2002년도 춘계학술발표논문집
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• pp.59-64
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• 2002

프레스 금형의 부품제작에 주로 사용되는 와이어 컷 방전가공에서 가공횟수가 펀치와 다이 블록의 가공면조도에 미치는 영향을 고찰하고자 수행하였다. 본 연구의 수행을 위해 정 밀 가공 기술로 활용도가 증가되고 있는 와이어 컷 방전가공기(Sodic A500H)를 사용하여 1차, 2차, 3차 총 3회 가공을 실시하였다. 3회에 걸쳐 가공된 펀치와 다이블록의 가공면조도 고찰을 위해 표면조도거칠기 측정기(Federal 사의 System5000)를 사용하여 연구를 수행하였다.

• 한국산학기술학회논문지
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• 제3권2호
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• pp.69-73
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• 2002

프레스 금형의 부품제작에 주로 사용되는 와이어 컷 방전가공에서 가공횟수가 펀치와 다이블록의 가공면조도에 미치는 영향을 고찰하였다. 본 연구의 수행을 위해 정밀 가공기술로 활용도가 증가되고 있는 와이어 컷 방전가공기(Sodic A500H)를 사용하여 1차, 2차, 3차 총 3회 가공을 실시하였다. 3회에 걸쳐 가공된 펀치와 다이블록의 가공면 조도 고찰을 위해 표면조도거칠기 측정기 (Federal사의 System5000)를 사용하여 연구를 수행하였다.

• 한국정밀공학회지
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• 제14권9호
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• pp.80-89
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• 1997

Die sinking electrical discharge machining(EDM) was conducted for ceramic composite of 33 weight percent TiC based on AI$_{2}$O$_{3}$ ceramic matrix according to the change of current and duty factor(DF). Material removal rate(MRR) was increased as the current and the duty factor increased, but better surface mor-pholoty was obtained in the region of lower current and duty factor. From the scanning electron microscopy(SEM) photographs and the energy dispersive X-ray spectroscopy(EDX) of the EDMed surface, EDM trace formed by one discharge spark was analyzed. Although the bending strength after EDM was highly decreased, reliability obtained by weibull analysis was increased twice. The bending strength was recovered or more by barrel polishing after EDM. From the FEM analysis of temperature for one spark, the possible melting region of AI$_{2}$O$_{3}$and TiC was obtained.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.827-831
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• 1997

Conductive veramic matrix composite(CMC) workpiece of TiC 33%/Al /sab 2/O /sab 3/ 66% Y /sab 2/ O /sab 3/ was machined by die sinking electrical discharge machining(EDM) according to different pulse duration and suty factor for reverse polarity of electrode. Material removal rate(MRR) was examined by process under various operating conditions. The surface morphology was evaluated by surface roughness values and scanning electron microscopy(SEM) research. The more MRR was obtained according to increase pulse duration and duty factor. Also the maximum surface roughness(Rmax) of EDMed surface was slightly changed with increased pulse duration and duty factor. The SEM photographs of EDMed surface showed wide recast wide recast distribution region of melting materials in purse duration 0.130(ms) than 0.048(ms).

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.473-477
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• 2000

The experimental study of die-sinking electrical discharge machining(EDM) was conducted for Cold Die Alloy Steel of SKD-11 with rotary electrode according to the peak current of 11A, 15A and 19A, and the duty factor of 0.24, 0.45. dielectric fluid flow through the electrode inside according to the change of electrode internal diameter during the EDM working. Material removal rate(MRR) was increased with flushing & rotation of electrode at the condition for the peak current of 15A, 19a but the MRR is decreased at the flushing only. The more surface roughness was obtained for the case of the flushing & rotation under the peak current of 19A.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.46-50
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• 1996

Die sinking Electrical Discharge Machining(EDM) of TiC/Al$_2$O$_3$Ceramic Matrix Composite(CMC) was conducted for positive and negative polarity according to the change of current and Duty Factor(DF). Also FEM analysis about temperature distribution of workpiece by one spark was executed. Maximum surface roughness( R$_{max}$ ) and SEM photographs of the EDMed surface for different conditions were evaluated. Higher Material Removal Rate(MRR) was obtained for negative polarity than positive one. Better surface morphology was found as the current is decreased, but the MRR was also decreased. From the SEM photographs, the size of melt cavity due to one spark is about 100 to 150${\mu}{\textrm}{m}$ in diameterer

• 한국공작기계학회논문집
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• 제10권6호
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• pp.126-134
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• 2001

Recently, high productivity and cost reduction becomes the most important target of industries due to the worldwide economic competition. One of these efforts is High Speed Machining(HSM), which reduces machining time with the increase of machining speed such as cutting speed and feedrate. It is very important, especially in case that the portion of machining time in production cost is high. This research suggests optimum cutting conditions to reduce cutting time with minimizing term error. For this study, a comprehensive model representing the texture of machining surface is developed, including rubbing phenomenon on the tip of ball end mill and expanded fibbing zone trajectory caused by tool deflection. Experiments show that the suggested set of feed and pick feed is optimum for maintaining the surface roughness identified by rubbing and low cutting speed in minimum.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.78-83
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• 2009

In general, Light-hardening polymer was used UV nanoimprint technology. A light-hardening polymer was had the problem of poor hardness, durability. In order to overcome the problem of polymer, inter change optical glass. However glass is very manufacture and a lowering of standars transmittance. In order to glass recover was necessary polishing process. The process is magnetorheological fluids polishing. MR polishing has been developed as a new precision finishing technique to obtain a fine surface. Hence, Magnetorheological fluids has been used for micro polishing to get micro parts. This polishing process guarantees high polishing quality by controlling the fluid density electrically. The applied material in experiments is fused silica glass. Fused silica glass is widely used in the optical field because of high degree of purity. For MR polishing experiments, MR fluid was composed with DI-water, carbonyl iron and nano slurry ceria. The wheel speed and electric current were chosen as the variables for analyzing the characteristics of MR polishing process. Outstanding surface roughness of Ra=1.58nm was obtained on the fused silica glass specimen. And originally glass transmittance was recover on the fused silica glass.

• 한국정밀공학회지
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• 제16권8호
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• pp.9-15
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• 1999

Die-sinking electrical discharge machining(EDM) for conductive ceramic matrix composite(CMC) of Tic/$Al_2O_3$ was experienced with addition of ultrasonic emission, and the results were compared with ones obtained by the EDM only. From this experimental study, the values of material removal rate(MRR) and surface roughness($R_{max}$), scanning electron microscope(SEM) micrographs, and weibull probability distribution of bending strength for the specimens were obtained and compared. The trend of MRR was found to be increased slightly with the current and the duty factor for both EDM only and EDM with ultrasonic emission. The MRR values were found to be increased for EDM with ultrasonic emission. The SEM micrographs of EDMed surface by under various operating conditions showed less micro cracks in various places. Although smaller bending strength value was obtained by EDMed surface with ultrasonic emission by weibull probability distribution analysis of bending strength.