• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.104-111
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• 2008

The objective of this study is to evaluate micro end-milling characteristics and tool wear behavior of AlN-hBN composites. First, AlN based composites with hBN contents in the range of 10 to 20vol% were prepared by hot-pressing. Vickers hardness and flexural strength of the prepared composite specimens were measured and compared according to the vol% of hBN variations. Then, cutting force variations were measured and analyzed using a tool dynamometer during the micro end-milling experiments; and machined surface shapes and roughness were investigated using a 3D non-contact type surface profiler. After micro end-milling, worn tools were investigated using a tool microscope and SEM images. From the experimental results, it can be observed that the cutting forces decreased, and surface qualities were improved with increasing hBN contents. At low content of hBN, tool chipping was observed; and tool wear rate decreased with increasing hBN contents. The results of this study insist that proper machining conditions, including tool wear behavior investigation, should be determined for the micro end-milling of AlN-hBN composites for its further application.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1171-1174
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• 2005

Manufacturing capability at the micro or nano scale production field is requested strongly in view of parts and product miniaturization. Miniaturized parts and products will introduce lots of benefits in terms of high precision functionality and low energy consumption. This paper presents the results of micro milling machine tool development for micro machining process. Finite element analysis has been performed to know the relationship between design dimensional variables and structural stiffness in terms of static, dynamic, thermal aspects. Performance evaluation through machining has been tested and discussed for achievable machining characteristics.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.129-133
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• 2007

Focused Ion Beam(FIB) systems is a useful tool for the fabrication of micro-nano scale structures. In this study, the effects of FIB etching on the Au microstructure are systematically investigated. As the fabrication parameters, ion dose, dwell time and beam overlap ratio are studied. First, the increases of Ga ion dose makes the milling yield higher and the sidewall of milling profile steeper. Dwell time is found to have little effects on the milling profile due to the relatively large milling area of $1\times1{\mu}m^2$ used in this study. However, beam overlap significantly affects not only milling rate but also milling profile. As the beam overlap ratio changes from positive to negative, the development of regular cross-stripe patterns at the bottom with low milling rate is observed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.468-472
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• 2005

In this paper, the static and dynamic stiffness of the air bearing stage for micro-micro machine tool are examined experimentally. For stiffness and precision concerns, air bearing stages are adapted for 3-axis micro-milling machine which is size of $200x200\;mm^2$. The air bearings in the stage are preloaded by permanent magnets to achieve desired bearing clearance and stiffness for vertical direction. As the stiffness of the air bearing is primary interests, static stiffness test were performed on XY stage in Z direction and Z column in Y direction. Dynamic test were performed on XY stage and Z column, respectively. Both static and dynamic tests were performed in different air pressure conditions. The vertical stiffness of XY stage is about 9 N/ pm where Y stiffness of Z column is much smaller as $1\;N/{\mu}m$ because of the large moment generated by Y force on the column.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.20-26
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• 2012

Recently, micromilling process has been progressed to meet the variety of the industry demands in micromolds and precision components. As a result, more and more commercialized micro tools and machines become available during last few years. This paper reviews the recent progress of micromilling technology in last five years. The results in process, machine tools, and micro tool fabrications are discussed.

• Design & Manufacturing
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• v.2 no.1
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• pp.27-31
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• 2008

The object of this study is a manufacture of buff die using CAM systems. Systems are consist of AutoCAD, CAM software and CNC milling machine. CAM software is purpose of G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for networking.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.109-117
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• 2003

With development of high advanced technologies and skills, micro machining techniques also are being more functional and smaller. Some of the recently developed micro machining technologies are micro drilling, micro EDM, WEDG, LBM, micro milling, micro UVM etc. In these micro machining techniques, Micro -EDM is generally used for machining micro holes, pockets, and micro structures in difficult-cut-materials. For machining micro structures, first of all, tool electrode should be fabricated by WEDG process. In micro-EDM, parameters such as peak current, pulse width, duration time are very important to fabricate the tool electrode and micro structures. Developed experimental equipments are composed of RLC circuit with PWM. In this paper, using developed micro EDM machine, the characteristics of micro electro discharge machining are investigated at micro holes, slot, and pocket machining etc. Also the trends of tool wear are investigated in case of hole and slot machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.482-486
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• 2004

The application of focused ion beam (FIB) technology in micro/nano machining has become increasingly popular. Its use in micro/nano machining has advantages over contemporary photolithography or other micro/nano machining technologies, such as small feature resolution, the ability to process without masks and being accommodating for a variety of materials and geometries. This paper presents that the recent development and our research goals in FIB nano machining technology are given. The emphasis will be on direct milling, or chemical vapor deposition techniques (CVD), and this can distinguish the FIB technology from the contemporary photolithography process and provide a vital alternative to it. After an introduction to the technology and its FIB principles, the recent developments in using milling or deposition techniques for making various high-quality devices and high-precision components at the micro/nano meter scale are examined and discussed. Finally, conclusions are presented to summarize the recent work and to suggest the areas for improving the FIB milling technology and for studying our future research.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.407-412
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• 2005

For micro electrochemical machining (ECM), tool electrodes with various sizes and shapes are necessary. In this paper, tool electrodes were fabricated by micro electrical discharge machining (EDM). Electrode material is tungsten carbide which has high rigidity and good conductivity for micro electrochemical machining. Disk-type and sphere-type electrodes were fabricated to prevent taper shape of side walls or to produce spherical features. Various 3D micro structures were fabricated by electrochemical milling with developed electrodes.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.2
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• pp.143-148
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• 2016

A micro end mill is one of the precise tools used in machining ultra-precision products such as microchannel and micropatterned mold. To achieve the required precision of these products, several studies investigated the cutting force, burr formation, and burr generation mechanism of micro end mills; however, there are few studies on the alignment of micro tools, which is the foundation of machining. Hence, in this investigation, relation expressions were derived to determine the relation between the misalignment parameters and the machining accuracy. At the same time, the effect of the machining parameters was analyzed using a multiple linear regression analysis and the analysis of variance. The results indicate that the tilting angle of a micro tool has more influence on the machining accuracy than other parameters.