• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.81-87
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• 1998

High-speed machining is one of the most effective technologies to improve productivity. Because of the high speed and high feedrate, high-speed machining can give great advantages for the machining of dies and molds. In this paper, high-speed machining for HP-4 die material was carried out with a coated tungsten carbide ball endmill. In the high-speed machining, the cutting force and surface roughness of workpiece show various characteristics in different cutting conditions. Especially, the surface roughness of the workpiece depends largely on pick feed and feed-per-revolution of the ball endmill. In the condition where pick feed and feed-per-revolution are equal, better surface roughness is measured. By obtaining good surface roughness at high speed, efficiency of machining can be increased.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.6
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• pp.105-112
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• 2007

Tungsten wire micro electrochemical machining (W-wire micro ECM) with ultra-short pulses enables precise micro machining of metal. In wire micro ECM, platinum wire has been used because it is electrochemically stable. However, the micro metal wire with low strength is easily deformed by hydrogen bubbles which are generated during the machining. The wire deformation decreases the machining accuracy. To reduce the influence of hydrogen bubbles, in this paper, the use of tungsten wire was investigated. To improve machining accuracy, suitable pulse conditions which affect generation of bubbles were also investigated. The tungsten wire micro ECM can be applied to the fabrication of various shapes. Using this method, various micro-parts and shapes were fabricated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.22-27
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• 2007

This study aims to find the optimal cutting conditions, when ellipse mirrors consisted Aluminum alloy were made it the Millimeter-Wave Interferometer System mirror with several tools on the High-Speed Machine. Machining technique for precision machining characteristics of ellipse mirrors consisted Al6061 matter by Ball endmill is reported in this paper., Results of machining on the High-Speed Machine(using NCD(Natural Crystalline diamond), WC and coated TiAlN ${\phi}6mm$ ball endmill tool) had measurement of surface roughness and form accuracy with cutting conditions(the Feed rate, the Depth of cut and the Cutting speed). the Millimeter-Wave Interferometer System ellipse mirror had been machined foundational precision machining characteristics of aluminum.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.3
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• pp.125-130
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• 2017

In this study, the influence of various factors on surface roughness was investigated using the Taguchi experimental method through high-speed machining processing. Feed rate, pitch, tool diameter, and depth of cut are widely applied to high-speed machining conditions for mold production. Each of these factors was implemented and classified into three levels; then, after high speed machining, surface roughness was measured, the S/N ratio was analyzed, and the influence on the surface roughness of control factors was analyzed quantitatively by ANOVA. Using this information, a mathematical model for predicting surface roughness was derived from multiple regression analysis. This mathematical model enables the surface roughness value after high-speed machining to be predicted at the production stage, before machining, for a wide range of machining conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.698-701
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• 2005

We have investigated experimentally a nano patterning using electron beam lithography for the nickel stamper fabrication. Recently, DVD and Blu-ray disk(BD) have nano-scale patterns in order to increase the storage density. Specially, BD has 100nm-scale patterns which are generally fabricated by electron beam lithography. In this paper, we found optimum condition of electron-beam lithography for 100nm-scale patterning. We controlled various conditions of EHP(acceleration voltage), beam current, dose and aperture size in order to obtain optimum conditions. We used 100nm-thick PMMA layer on a silicon wafer as photoresist. We found that EHP was the most dominant factor in electron-beam lithography.

• Design & Manufacturing
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• v.17 no.1
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• pp.7-12
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• 2023

Recently, with the emergence of the 4th industrial revolution, the demand for smart factories and factory automation is increasing. In this study, a tool life prediction program was developed to select optimal machining conditions using CNC milling equipment, which is widely used in flexible production and automation. The equipment used in the experiment was Hwacheon Machine Tool's 5-axis machining equipment, and the tool used was a 17F2R tool. For the machining path, the down-milling cutting method was selected and long-term machining was performed. The analysis standard for side wear on the tool was set at 0.1 to 0.2 mm, and tool life data and wear data were obtained in the cutting experiment. The program was created through the data obtained from the experiment, and a prediction rate of over 90% was secured when comparing the experimental data and the predicted data.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.190-195
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• 1997

The requirement of precision products about difficult-to-cut materials such as Cu and Aluminum alloy is becoming more and more. Because of soft materials, the exist narrow groves on surface are difficult to gotten off even on the polishing stage. It has been proved that Magnetic-Electrolytic-Abrasive Polishing (MEAP) is a efficient method to resolve this problem by using the nonwoven-abrasive pads together [1, 2]. In this study, through the experiments, their machining properties of newly developer polishing material of SiC, Al2O3 and diamond nonwoven abrasive pads have been proved. Through the experiments, the optimal machining conditions on larger cylinder shape workpiece of Cu and Aluminium alloy have been found, through the Taguchi[3] method the optimal machining conditions can be selected.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.163-168
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• 2005

It is one of the most important things to determinate optimized cutting conditions which satisfy productivity and cost simultaneously in production and CAPP systems. These days many researchers have figured out the optimizing way for solutions of multi-object function to find the approach methods using algorithm such as genetic algorithm or tabu search, etc., instead of mathematical methods. The main creation of objective function is proposed by empirical method but which is difficult to set it up and to analysis. In this paper, an optimization method of cutting condition is shown using the ANN and GA for the multi-objective function in high speed machining.

• Journal of the Korean Ceramic Society
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• v.30 no.5
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• pp.420-426
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• 1993

The machinability of ceramics has been experimentally studied. The experiments were conducted on alumina cernmics of various purity, quartz, and cordierite using the sintered diamond tools and CBN tools. Tool wasre, surface roughness, and cutting resistence were measured and analysed. It was found that the workpieces could be machined with the diamond and CBN tools, but the sintered diamond tools were more efficient for the machining of the high strength ceramics. The machining of alumina ceramics with sintered diamond tools showed that (1) wet machining prolonged tool life comparing with dry machining, (2) workpiecewith higher purity had better surface roughness, (3) severe cutting conditions led to the chipping and fracture of tool and increase of the surface roughness and cutting resistance, (4) 20~40m/min of cutting speed, 0.01~0.02mm/rev of feed, and 0.1~0.2mm of cutting depth are suggested as proper cutting conditions for the high strength ceramics.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.50-56
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• 2007

This study aims to find the optimal cutting conditions, when are IR Detection device HgCdTe is machined with diamond tool of diamond turning machine. Machining technique for HgCdTe with single point diamond turning tool is reported in this paper. The main factors influencing the machined surface quality are discovered and regularities of machining process are drawn. It has been found HgCdTe has more and more important applications in the field of modern optics. The purpose of our research is to find the optimum machining conditions for ductile cutting of HgCdTe and apply the SPDT technique to the manufacturing of ultra precision optical components of brittle materials.