• 한국생산제조학회지
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• 제5권1호
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• pp.9-16
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• 1996

This is an experimental investigation of the temperature generated in a cutting tool during the machining of stainless steel. The temperature results from the wear of the cutting tool are considered in order to investigate the relation between cause and effect of these factors. This possibility has been tested using a thermocouple technique to record temperature vs. time curves for a variety of cutting conditions. This is done by employing a thermocouple inserted on the tool tip near the major cutting edge. Temperature distributions are calculated using finite element method and compared to the contour maps measured by an optical system. It suggests that the temperature gradients and the tool performance will be dependent on certain facotrs in tool geometry when cutting this material.

• 한국공작기계학회논문집
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• 제11권4호
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• pp.75-81
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• 2002

In this study, experiments were carried out to investigate the characteristics of grinding and wear process of diamond wheel during grinding ceramic materials. Normal component of grinding resistance was decreasing while increase of spindle speed. The resistance of vitrified bond wheel was less then that of resinoid bond wheel because of imbedded large holes on the surface of cutting edge. Surface roughness was decreasing while increase of spindle speed. The surface roughness using vitrified bond wheel was less than that of resinoid bond wheel because of small elastic deformation. After continuous finding of ceramics, cutting edge ratio of resinoid bond wheel decreased. For the case of vitrified bond wheel, cutting edge ratio did not change.

• 한국생산제조학회지
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• 제19권1호
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• pp.1-6
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• 2010

Inconel 718 alloy has been applied to high temperature, high load and corrosion resistant environments due to its superior properties. However, This alloy is a difficult-to-cut nickel-based superalloy and the chipping or notch wear is mainly generated on the cutting edge of the tool. In this study, the machinability of Inconel 718 is investigated to improve tool life under various cutting conditions with TiCN-based coated ball-end mills. The cutting conditions can be suggested to improve both the tool life and machined surface quality in Inconel 718 high speed machining.

• 대한금속재료학회지
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• 제48권7호
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• pp.651-659
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• 2010

When high-speed interrupted cutting is carried out for die and mold steels with high hardness, CBN tools manifested a significantly longer wear life than carbide, ceramic, or cermet tools in an experiment of face milling characteristics. In addition, it was also found that they secured a stable surface roughness within a range of 1.6 S~6.3 S, an acceptable range for precision machining for polished machining parts. And it makes them acceptable in the precision machining field, except in industries where very high machining accuracy is required. In the high hardness interrupted cutting, it was advantageous to perform a negaland treatment and a honning treatment on the tools' cutting edge to extend tool life and surface roughness. Also, severe crater development was found on the sloped face in CBN tools following high-speed machining. This caused the cutting edge to be weakened and damaged, and ultimately resulted in a shorter tool life. Finally, as a result of EDX mapping inspection, Cr component was detected evenly on the entire crater wear area, which can be included only in STD 11.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.84-87
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• 2001

The high speed machining which cam improve the production and quality has been remarkable in die/mold industry with the growth of parts and materials industries. The speed of machine tool increases, but on the other hand, the response of sensors I not being improved. Therefore, the condition monitoring techniques for the machine too, tool and workpiece in high speed machining are incomplete. In this study, characteristics of the tool edge roughness were verified from the high frequency components of cutting force signals acquired by the high speed dynamometer. Also, the experimental evaluation technique for the machinability and condition monitoring in high speed machining was established by analyzing the cutting force, acceleration and surface roughness.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.344-348
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• 2001

In this study, experiments were carried out to investigate the characteristics of grinding and wear process of diamond wheel grinding ceramic materials. Normal component of grinding resistance was decreasing while increase of spindle speed. The resistance of vitrified bond wheel was less then that of resinoid bond wheel because of imbedded large holes on the surface of cutting edge. Surface roughness was decreasing while increase of spindle speed. The surface roughness after using vitrified bond wheel was less than that of resinoid bond wheel because of small elastic deformation. After continuous grinding of ceramics, cutting edge ratio of resinoid bond wheel decreases. For the case of vitrified bond wheel, cutting edge ratio does not change.

• 한국정밀공학회지
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• 제19권5호
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• pp.133-138
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• 2002

The technique of high speed machining is widely studied in machining fields, because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool fur high speed machining in not close behind that of machine tool. In this study, 10 types flat endmill is prepared for obtaining data according to tool shape. Especially, we concentrated in helix angle, number of cutting edge and rake angle. Cutting condition is selected for several experiments and measuring cutting farce, tool life, tool wear and chip shape according to cutting length. 3-axis cutting farces are acquired from the tool dynamometer with high natural frequency, as the conventional tool dynamometer (9257B, Kistler) has cannot measure the state of high frequency force. Particularly, we found out that the axial cutting force waveform has a good relation with tool wear features. And flow is interrupted at the beginning of cutting by the decrease of rake angle. By above results. it is suggested the endmill tool with 45$^{\circ}$helix angle, 6 cutting edge and -15$^{\circ}$rake angle is suitable for high speed machining.

• 한국정밀공학회지
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• 제31권5호
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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.

• 한국정밀공학회지
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• 제18권5호
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• pp.130-136
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• 2001

Generally, a metal slitting saw is plain milling cutter with thickness less than 3/16 inch. This is used for cutting a workpiece that high dimensional accuracy and surface finish is necessary. A small thin milling cutter like a metal slitting saw is useful for machining a narrow groove. In this case, built up edge(BUE) is severe at each tooth and affects the surface integrity of the machined surface and tool wear. It is well known that tool geometry and cutting conditions are decisive factors to remove BUE. In this paper, we optimized the geometry of the milling cutter and selected cutting conditions to remove BUE by the experimental investigation. The experiment was planned with Taguchi method based on the orthogonal array of design factors such as coating, rake angle, number of tooth, cutting speed, feed rate. Response table was obtained from the number of built-up edge generated at tooth. The optimized tool geometry and cutting conditions could be determined through response table. In addition, the relative effect of factors was identified bh the analysis of variance (ANOVA). Finally, coating and cutting speed turned out important factors for BUE.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.951-954
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• 2000

This paper presents a new cutting method, i.e. diamond cutting, aided by electrolysis, in order to cut ferrous materials with diamond tools. Diamond cutting is widely applied in manufacturing ultraprecision parts such as magnetic disk, polygon mirror, spherical/non-spherical mirror and copier drum, etc. because of the diamond tool edge sharpness. In general, however, diamond cutting cannot be applied to cutting steels, because diamond tools wear excessively in cutting iron based materials like steel due to their high chemical interaction with iron in high temperature. In order to suppress the diffusion of carbon from the diamond tool and to reduce increase of cutting force due to size effect, we attempt to change chemically the compositions of iron based materials using electrolysis in a limited part which will be soon cut. Through experiments under several micro-machining and electrolysis conditions, cutting using electrolysis, compared to conventional cutting, was found to result in a great decrease of the cutting force, a better surface and much less wear tool.