• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.38-42
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• 2001

In the machining of glass fiber reinforced plastics(GFRP), turning has been often used. But the most of past studies have been interested in the effect of fiber orientation on tool wear. In this study, the effects of fiber contents and cutting speeds on tool wear, cutting force and surface roughness are investigated experimentally. By proper selection of cutting tool, the variables are cutting speed, fiber contents and cutting length with fixed feed rate and depth of cut. The fiber contents have major effects on coated tool wear which observed as abrasive wear type.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.169-172
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• 1995

In optmizing cutting condition for face milling operation, tool wear is an important maching factor. For the purpose of establishing the relationship between various maching factor and tool wear, cutting tests have been performed. As a result, hardness and chemical composition of workpiece material, chemical compositition and grain size of cutting tool and cutting speed have been selected as machining factor. In addition, relationship between feed rate and workpiece hardness has been observed. Prior to utilizing cutting condition recommended by 'Machining Data Hardbook(MDH)' as a Knowledge base, an analysis for the validity has been provided. Based on this analysis, tool life criteria applied by MDH has been modifiied. Finaly, using MDH recommended data for neural network trainning, we can compensate the result form the trained neural network for optimizing cutting condition for some given workpice and cutting tool.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.79-89
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• 1998

In determining optimal cutting condition for face milling operation, tool wear is an important factor. For the purpose of establishing the relationship between various machining factors and tool wear, cutting tests have been performed. As a result, hardness and chemical composition of workpiece material, chemical composition and grain size of cutting tool and cutting speed have been selected as machining factors. In addition, relationship between feed rate and workpiece hardness has been observed. Prior to utilizing cutting conditions recommended by ‘Machining Data Handbook(MDH)’ as a knowledge base, an analysis for the validity of the MDH has been provided. Based on this analysis, tool life criteria applied by MDH has been modified. Finally, using MDH recommended data for neural network trainning, the results from the trained neural network for optimal cutting condition for some given workpiece and cutting tool can be used as reference cutting conditions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.28-35
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• 2013

Micro electrical discharge machining (EDM) as a non-contact machining process is very effective for micromachining with a thin electrode because of its low machining reaction force. The micro-electrode machining device has the advantage of maintaining high precision through the whole processes and uses a feeding wire in the thin electrode tool manufacturing process. This study describes the design and evaluation of a micro-electrode machining device using optical photo-interrupter. The electrode was fabricated by reverse electrical discharge machining. The performance of designed system was evaluated to measure tension force according to feed speed of wire. This system for micro electrode fabrication proves the feasibility in the micro-EDM process of the micro holes and parts for industrial applications.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.110-115
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• 2012

For domestic aircraft industry, not mass production of components is limited, small production scale of the order is made by part because many kinds of hundreds of thousands of kinds of small quantity batch production system are taking. But the high reliability and stability are required during the processing because they require high precision parts are required. It is found that when C-axis rotation speed was increased, the diameter of the cutting tool decreased with increasing surface roughness, while the turn-mail feed rate was increased with increasing the surface roughness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.903-906
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• 1997

For the net shape manufacturing, grinding is a important process that influences directly the accuracy and the integrity of products. We studied and researched the grinding force, surface roughness, and grinding wheel durability, according to the change of a feed speed of the table and a depth of the cut step by step with experiment that it is used to WA wheel. Workpiece materials were used STDII. The purpose of this study proposes the basic data for design of the machine tool and for controlling the machining parameters to obtain optimum performance of plunge grinding system during operation.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.3
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• pp.68-76
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• 1986

The surface rolling method which is one of the plastic deformation processes increases the surface roughness and hardness of materials. In this study, three NACHI6000 ZZ bearing were used for surface rolling tool on the mild steel and high carbon steel. The purpose of this study is to investigate the effects of rolling speed, feed rate and contact pressure on the surface roughness. The following results have been obtained with the mild steel and high carbon steel. 1. The roller finishing method has increased surface roughness from 2.4 .mu.m Ra at initial ground surface to 0.17 .mu.m Ra-0.4 .mu.m Ra. 2. The contact pressure has influenced greatly on the surface roughness. There is an optimal contact pressure. 3. As the rolling speed and the feed rate decrease, the surface roughness improves. 4. The optimal contact pressure for the good surface roughness of SS40 and STC 3 has been at 213 Kgf/Cm$^{2}$ and 220 Kgf/Cm$^{2}$ respectively.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.370-375
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• 2002

Recently, the interest on micro optical parts has increased rapidly with the development of technology related to microsystems. Among the optical parts, micro lens is one of the most broadly used micro parts. To mass-produce the micro lenses, it is very effective to use the mold insert and injection molding process. There are many methods to fabricate the mold insert for micro lenses: electroforming, etching, mechanical micromachining and so on. In this study, we fabricated the mold insert for micro lenses using a micro ball endmill to apply mechanical micromaching method and analyzed the effect of main process parameters such as spindle speed, feed rate, dwell time on the processed surface. Then, using fabricated the mold insert we fabricated the micro lenses through injection molding process.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.123-130
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• 2006

In manufacturing, process automation and parameter optimization are required in order to improve productivity. Especially in welding process, productivity and weldablity should be considered to determine the process parameter. In this paper, optimization methodology was proposed to determine the welding conditions using the objective function in terms of productivity and weldablity. In order to conduct this, welding experiments were carried out. Tensile test was performed to evaluate the weldability. Neural network model to estimate tensile strength using the laser power, welding speed, and wire feed rate was developed. Objective function was defined using the normalized tensile strength which represented the weldablilty and welding speed and wire feed rate which represented the productivity. The optimal welding parameters which maximized the objective function were determined.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.266-272
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• 2002

High-speed machining is one of the most effective technology to improve productivity. Because of the high speed and hugh fried rate, high-speed machining can alive great advantages for the machining of dies and molds. This paper describes on the improvement of machining accuracy in high-speed machining. Depth of cut, feed rate and spindle revolution are control factors. The effect of the control factors on machining accuracy is discussed fur the results of surface roughness and machining error in Z-direction of the high speed machining.