• Design & Manufacturing
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• 제14권2호
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• pp.56-61
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• 2020

Recently, research for machining next-generation micro semiconductor processes and micro patterns has been actively conducted. In particular, it is applied to various industrial fields depending on the machining method in the case of FIB (Focused ion beam) milling. In this study, intends to deal with FIB milling machining technology for ultra-precision diamond tool fabrication technology. Ultra-precision diamond tools require nano-scale precision, and FIB milling is a useful method for nano-scale precision machining. However, FIB milling has a problem of Gaussian characteristics that are differently formed according to the beam current due to the input of an ion beam source, and there are process conditions to be considered, such as a side clearance angle problem of a diamond tool that is differently formed according to the tilting angle. A series of process steps for fabrication a ultra-precision diamond tool were studied and analyzed for each process. It was confirmed that the effect on the fabrication process was large depending on the spot size of the beam and the current of the beam as a result of the experimental analysis.

• 한국공작기계학회논문집
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• 제10권4호
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• pp.55-64
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• 2001

In this study, hemisphere and cylindrical shapes were machined for different tool paths and machining conditions with ball endmill cutters. Tool deflection, cutting forces and shape accuracy were measured according to the inclination position of the sculptured surface. As the decreasing of inclination position angle, the tool deflection was increased due to the decreased cutting speed when the cutting edge is approaching toward the center. Tool deflection when upward cutting is obtained less than that of downward cutting and down-milling in upward cutting showed the least tool deflection for the sculptured surface. Roundness values were found in least roundness error when down-milling in upward cutting. It is obtained the very little difference between 90。and 45。 of inclination position angle. The best surface roughness value was obtained in upward up-milling and showed different tendency with tool deflection and cutting force. For down-milling, the cutting resistance of the side wall direction is larger than that of feed direction. Therefore, this phenomenon which is received over cutting resistance can be caused of chatter.

• 대한기계학회논문집A
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• 제35권8호
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• pp.899-904
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• 2011

본 연구는 마이크로 머시닝을 적용한 유동채널가공에서 버의 발생과 제거에 관한 연구이다. AISI316 스테인리스강의 마이크로 유동채널가공은 마이크로 밀링과 자기 디버링을 결합하여 실시하였다. 먼저 마이크로 밀링으로 유동채널을 가공하였고, 가공조건에 따라 마이크로 채널주변에 미소 버가생성됨을 확인하였다. 미소 버를 제거하기 위해서 자기 디버링을 행하였다. AISI316 스테인리스강은 비자성체로 자기연마에 큰 영향을 미치는 자속밀도가 매우 낮은 금속이다. 본 연구에서는 공작물의 자속밀도를 향상시키기 위해서 자기 테이블을 개발하여 이를 자기연마 디버링에 적용하였고, 주사전자현미경(SEM)과 표면형상기로 자기 디버링에 의한 버의 제거효과를 측정하였다.

• 한국공작기계학회논문집
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• 제13권6호
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• pp.17-22
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• 2004

A study for investigating the effects of the cutting conditions (radial depth of cut feed per tooth) and the number of tooth on the side wall of prismatically milled workpiece is described. This study is available not only for understanding the geometrical characteristics of the end milled side wall but also for finding the optimal cutting conditions. In this work, the side wall geometry was characterized by the straightness and the location of maximum peak point. Through this study, it was revealed that the geometrical characteristics of the end milled side wall are strongly related to the material removal per tooth and the number of tooth.

• 한국기계가공학회지
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• 제1권1호
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• pp.5-14
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• 2002

Hemisphere shapes were machined for different tool paths and machining conditions with ball endmill cutters. It was also found out how feedrate affect the precision of the machining and also tried to study the most suitable feedrate in specific cutting condition. Tool deflection, cutting forces and shape accuracy were measured according to the inclination position of the sculptured surface. As the decreasing of inclination position angle, the tool deflection was increased due to the decreased cutting speed when the cutting edge is approaching toward the center. Tool deflection when upward cutting IS obtained less than that of downward cutting and down-milling in upward cutting showed the least tool deflection for the sculptured surface. For down-milling, the cutting resistance of the side wall direction is larger than that of feed direction. It was found that the tool deflection is getting better as tool path is going to far from the center for convex surface.

• 한국기계가공학회지
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• 제10권1호
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• pp.1-7
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• 2011

Micromachining is gaining popularity due to recent advancements in MEMS(Micro Electro Mechanical Systems). Using conventional micromachining, it is relatively difficult to produce moving components in the order of microns. Photolithography for silicon material has high accuracy machining, but it has low aspect ratio. X-ray lithography has ultra high accuracy machining, but it has expensive cost. Micro-EDM(electro discharge machining) has been gaining popularity as a new alternative method to fabricate micro-structures. In this study, Micro-EDM machine is developed available for fabricate micro-structures and two processes such as side cut EDM and milling EDM is proposed. Several sets of experiment results have been performed to study the characteristics of the machining process.

• 한국생산제조학회지
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• 제8권3호
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• pp.83-91
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• 1999

In this paper, we suggest a virtual machining system that can simulate cutting forces of ball end milling at the stage of part design. Cutting forces, here, are estimated from the machanistic model that uses the concept of specific cutting farce coefficient. To this end, we need undeformed chip thickness which is used for calculating chip load. It is derived from the Z-map data of a CAD model. That is, chip load is the height difference between the cutting tool and the workpiece at an arbitrary position. The tool contact point is referred from the cutter location data. On the other hand, the workpiece height is acquired from the Z-map model of a CAD data. From the experimental verification, we can simulate machining process effectively to the slot and the side cutting of ball end mill.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.102-106
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• 1996

In the ball end-milling process of a 3-dimensional mold, it is important to select cutting conditions and tool path considering the geometrical shape of a workpiece to reduce machining time. In this study, experiments were performed to decide allowable feed rate not breaking stability of system for different geometrical shapes. It was found that downcut is more stable than upcutting in machining side wall and downward is preferable to upward in inclined part depending on the angle of the inclination and depth of cut.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.125-129
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• 1996

In this study, a method is proposed for the cutting force prediction of Ball-end milling process using Z-map is proposed. Any types of cutting area generated from previous cutting process can be expressed in z-map data. Cutting edge of a ball-end mill is divided into a set of finite cutting edges and the position of this edge is projected to the cross-section plane normal to the Z-axis. Comparing this projected position with Z-map data of cutting area and determining whether it is in the cutting region, total cutting force can be calculated by means of numerical integration. A series of experiments such as side cutting and upward/downard cutting was performet to verify the simulated cutting force.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.942-946
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• 1997

In this research,we suggest a virtual machining system that can simulate sutting forces at the stage of design. Cutting forces,here, are modeled form the machanistic model of the ball end milling. To this end, we need undeformed chip thickness which is used for calculating chip load. It is derived form the z-map data of a CAD model. That is, chip load is the height difference between the cutting tool contact point and the workpiece at arbitrary position. The tool contact point is referred from the cutter location. Form the experimental verification, we can simulate machining process effectively to the slot and the side cutting of ball end mill.