• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.75-80
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• 2000

This paper deals with the precision cutting characteristics of mono-crystal diamonds poly-crystal diamonds and tungsten carbide tool on ductile material. The cutting tests were carried out under various uncut chip areas and 20${\mu}{\textrm}{m}$ depth of engagement. The machinability in precision machining was discussed from the viewpoints of the normal cutting forces and the surface roughness of the workpiece. As the feed rate decreases the normal force difference for cutting edge radii appears to large. In various cutting edge radii the surface roughness difference when cut the copper which is ductile material than the aluminium alloy is large. As the same cutting condition the hardness value on cut surface with the diamond tool appears to be smaller than that of the tungsten carbide tool.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.190-196
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• 1999

In this study, a procedure for analyzing chip-tool friction and shear processes in 3-D cutting with a single point tool has been established. The edge of a single point tool including circular nose is modified to the equivalent straight edge, then 3-D cutting with a single point tool is reduced to equivalent oblique cutting. Transforming the conventional coordinate systems and using the measured three component of cutting forces, force components on the rake face and the shear plane of the equivalent oblique cutting system can be obtained. And it can be possible to assess the chip-tool friction and shear characteristics in 3-D cutting with a single point tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.943-946
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• 2002

This paper presents atomization characteristics of cutting fluids. To analyze the behavior characteristics of cutting fluid, analytical approach and experimental measurement were performed to predict the aerosol size, velocity and concentration due to cutting fluid atomization mechanism in machining operation. The established analytical model which is based on atomization theory analyzes the cutting fluid motion and aerosol generation in machining process. The predictive models can be used as a basis for environmental impact analysis on the shop floor. It can be also facilitate the optimization of cutting fluid usage in achieving a balanced consideration of productivity and environmental consciousness.

• Journal of Korea Foundry Society
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• v.29 no.1
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• pp.38-44
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• 2009

Magnetic separation of Fe contaminated Al-Si cutting chip scraps was performed for the recyclability assessment. It was also aimed to investigate the casting and solidification characteristics of the cutting chip scraps. The magnetically separated cutting chip scraps were adequately treated for the casting procedure and test specimens were made into a stepped mold inducing different cooling rates. The test specimens were evaluated by the combined analysis of ICP, Spectroscopy, OM-image analyzer, SEM/EDS, etc. Solidification characteristics of cutting chip scraps were examined as functions of Fe content and cooling rate. It is concluded that the magnetic separation process can be utilized to recycle the Fe contaminated Al-Si cutting chip scraps in the high cooling rate foundry process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.77-82
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• 2003

In end milling process, undeformed chip thickness and cutting force vary periodically with phase change of the tool. Recently, a model has been proposed to simulate the shear and friction characteristics of an up-end milling process in terms of the equivalent oblique cutting to this. In the current study, the varying undeformed chip thickness and the cutting forces in a down-end milling process have been replaced with the equivalent ones of oblique cutting. And, the down-end milling characteristics of SM45C has been compared with that of the up-end milling previously presented with different helix angles.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.97-101
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• 1996

In this paper, We have studied internal quality incluiding chemical compositions, microscopic structrue and nonmetalic inclusion of test materials. We have analyzed dynamic characteristics of cutting resistence including tensile strength value, hardeness value, impact value etcs. We have compared chip treatments of test materials. In analyzing internal quality, all of test materials have typical ferrite+pearlite structure. But, nonmetallic inclusion have oxide and sulfide inclusion in medium carbon steels, mainly sulfide inclusion is existed in S-free cutting steels. In Ca+S-free cutting steels, calcium aluminate and sulfide complex inclusion, had low-melting points, as deformation of sulfide and oxide inclusion is existed. machining characteristics, cutting resistence is maximum in Ca+S-free cutting steels, minimum in medium carbon steels. Chip treatements are excellent in S-free cutting steels, similar to the Ca+S free cutting steels and medium carbon steels.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.395-401
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• 2014

Development of five axis tool grinding machine and CAD/CAM systems increase tool design flexibility. In this research, investigated are cutting characteristics of ball-end mill with different helix angle. Special WC ball-end mills with $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$ helix angles are designed and used in various cutting tests. Machining performance according to helix angle variation is evaluated from cutting forces, surface roughness, tool wear, produced chip shape, and vibration characteristics. The ball-end mill with $10^{\circ}$ helix angle shows the best cutting performance due to appropriate chip load distribution and smooth chip flow. This research can be used for cutting edge geometry optimization and novel design of ball-end mill.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.89-95
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• 2001

Ceramic tool has to equip with not only high toughness and strength but also low thermal expansion and good thermal conductivity which leads to the high thermal shock resistance. These characteristics make it have longer tool life under thermal stress condition. In this study, commercial Si$_3$N$_4$ceramic cutting tool and home-made SiC based ceramic cutting tools which have different sintering time and chemical composition are tested under various cutting speed and the feed rate increase, the cutting force and the flank wear growth ratio increase, too. The performance of home-made SiC based ceramic cutting tool shows the possibility to be a new ceramic tool.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.211-216
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• 2016

Al alloys are useful materials having high specific strength and are used in machining of parts having thin-walled structures for weight reduction in aircraft, automobiles, and portable devices. In machining of thin-walled structures, it is difficult to maintain dimensional accuracy because machining deformation occurs because of cutting forces and heat in the cutting zone. Thus, cutting conditions and methods need to be investigated and cutting signals need to be analyzed to diagnose and minimize machining deformation and thereby enhance machining quality. In this study, an investigation on cutting conditions to minimize machining deformation and an analysis on characteristics of cutting signals when machining deformation occurs are conducted. Cutting signals for the process are acquired by using an accelerometer and acoustic emission (AE) sensor. Signal characteristics according to the cutting conditions and the relation between machining deformation and cutting signals are analyzed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.83-88
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• 2003

In this study, experiments were conducted with an ultra-precision machine, developed In domestic, to find the characteristics and the most suitable cutting conditions of ultra-precision machining. To maximize the performance of the machine, the machine was installed in a room that is protected from vibration and is maintained constant temperature and constant humidity. Selected work pieces are an aluminum-alloyed material, which has excellent corrosion resistance and has low deformation. The used tool is synthetic poly crystal diamond which has excellent abrasion resistance and has low affinity. Four types of tool nose radius were used such as 0, 0.1, 0.2 and 0.4mm. Machining is performed with cutting speed of 500, 800 and 1000m/min., feed rate of 0.005, 0.008, 0.010mm/rev. and cutting depth of 0.0005, 0.0025 and 0.005mm respectively which can generally be used in the field as a cutting condition. As a method of evaluation surface roughness was measured for each cutting condition and reciprocal characteristics are computed for each tool nose radius, cutting speed, feed rate and cutting depth. As a result the most suitable cutting condition and characteristics of ultra-precision machining were identified which can usefully be applied in the industrial field.