• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.977-980
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• 1997

Ultraprecision machining process and MEMS technology have been taken more and more important position in machining of micro parts such as PDP and IT components, as the application field of micro parts increases. A micro machining center is very effective equipment for the fabrication of micro parts, because of its benefits such as lower power consumption, high precision and lower machining cost. Therefore, we study the possibility of application to the micro machining of barrier ribs used in PDP and also analyse the machining characteristics. The fabricated barrier rib has 30~$200\mu\textrm{m}$ pitch and was made by the flat endmill with the diameter of 0.2mm, 40, 000rpm condition.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.2
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• pp.52-60
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• 2004

High-speed machining is one of the most effective technologies to improve productivity. Because of the high speed and high feed rate, high-speed machining can give great advantages for the machining of dies and molds. High speed machine tool makers try to find best machining condition with the one that they have built. Machine builders need to develop test specimen since it helps finding characteristics o( machine tools when the machining properties of the specimen are analyzed. This paper develops test specimen to identify features of the main spindle, the feeding device, and the frame of a machine tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.878-881
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• 2000

Recently high speed machining is being studied actively to reduce machining time and to improve machining precision. To perform efficient high speed machining, evaluation of high speed machinability must be studied preferentially and it can be identified by investigation of cutting force, tool wear and surface roughness. In this study. the cutting force and tool wear and surface roughness are investigated in case of various cutting conditions for hardened die steel.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.50-57
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• 2006

The investigation of microscopic precision in high speed endmilling is necessary for machinability evaluation, and the environmentally conscious machining technology have more important position in recent machining process. The microscopic precision of workpiece is influenced by machining environments variation as cutting fluid type and lubricant method. In this study, the cutting forces according to variation of cooling and lubrication are investigated by specially designed tool dynamometer. And the surface roughness, micro hardness and residual stress are evaluated according to machining environment. The characteristics of damaged layer in environmentally conscious machining and conventional machining using cutting fluid are compared experimentally.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1793-1797
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• 2003

After the micro turning lathe was developed in the last year by AMR Laboratory in Yeungnam university, a micromilling machine is developed for micro/meso machining. This machine is integrated with PZT-driven micro-sliders, micro-linear encoders, aerostatic spindle which has maximum 150,000 rpm. It is applicable to milling and drilling of micro scale. This paper presents the possibility of micro/meso machining and characteristics of micro end milling process by using micro machine. A machining of micro parts using 0.2 mm flat end mill was achieved by micro-milling machine. Experimental results show the machining capability and positional accuracy of this machine is good enough for machining micro parts.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.77-82
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• 2021

This numerical study focuses on the analysis of fume particle dispersion characteristics over the surface of target workpiece in laser micro-hole machining process. The effects of oblique stagnation flow over fume generating machining point are examined by carrying out a series of three-dimensional random particle simulations along with probabilistic particle generation model and particle drag correlation of low Reynolds number. Present computational model of fume particle dispersion is found to be capable of assessing and quantifying the fume particle contamination in precision hole machining which may influenced by different types of air flow patterns and their flow intensity. The particle size dependence on dispersion distance of fume particles from laser machining point is significant and the effects of increasing flow oblique angle are shown quite differently when slot blowing or slot suction flows are applied in micro-hole machining.

• Journal of Computational Design and Engineering
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• v.1 no.2
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• pp.128-139
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• 2014

This study investigates the effects of machining parameters as they relate to the quality characteristics of machined features. Two most important quality characteristics are set as the dimensional accuracy and the surface roughness. Before any newly acquired machine tool is put to use for production, it is important to test the machine in a systematic way to find out how different parameter settings affect machining quality. The empirical verification was made by conducting a Design of Experiment (DOE) with 3 levels and 3 factors on a state-of-the-art Cincinnati Hawk Arrow 750 Vertical Machining Center (VMC). Data analysis revealed that the significant factor was the Hardness of the material and the significant interaction effect was the Hardness + Feed for dimensional accuracy, while the significant factor was Speed for surface roughness. Since the equally important thing is the capability of the instruments from which the quality characteristics are being measured, a comparison was made between the VMC touch probe readings and the measurements from a Mi-tutoyo coordinate measuring machine (CMM) on bore diameters. A machine mounted touch probe has gained a wide acceptance in recent years, as it is more suitable for the modern manufacturing environment. The data vindicated that the VMC touch probe has the capability that is suitable for the production environment. The test results can be incorporated in the process plan to help maintain the machining quality in the subsequent runs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.915-918
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• 1997

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, an abrasive circulation system was designed and manufactured. As a result, it was found that a fine inner surface abrasive of pipe was available by the use of this machining methods. The basic machining characteristics of pin-type magnetic tools were analyzed experimentally. In addition, the experimental results show that we can realize that pin-type magnetic tools have more machining efficiency than iron particles as magnetic tools.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.993-998
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• 1997

The advanced technology of micro-machining is starting to penetrate our lives. This technology, with which it is possible to make micro-structures by means of processing on the order of nm (micrometer = 1/1,000 mm) or less, is realizing machines that were only part of our wildest imagination. However, the fact is that many issues remain in the quest for a variety of applications. With the advent of computing technologies, information technologies, and telecommunications technologies, we foresee the need for new approaches in design, process, and the use of materials, technologies, and people in a globalized manufacturing enterprise. A new thinking paradigm is needed to focus on quality of service on the products we design and manufacture. Factories in different regions need to be co-ordinated through use of the state-of-the-art information on productivity, diagnostics, and service evaluation of manufacturing systems could be shared among different locations and partners. In this research, We develope the internet based Diagnosis system for micro machining and evaluate its characteristics by using mechatronic sensor like Dynamometer, acoustic emission, Acceleration sensor, micro phone, vision, infra-red thermometer.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.61-66
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• 2010

Silicon nitride is widely used as an engineering ceramics because it has high strength, abrasion resistance and corrosion resistance even at high temperature. However, machining of silicon nitride is difficult due to its high hardness and brittleness. Laser assisted machining(LAM) allows effective cutting using CBN tool by locally heating the cutting part to the softening temperature of YSiAlON using the laser beam. The effect of preheating depending on process parameters were studied to find out the oxidation mechanism. If silicon nitride is sufficiently preheated, the surface is oxidized and $N_2$ gas is formed and escapes from the material, thereby making the cutting process more advantageous. During laser preheating process before machining, high temperature results in strong oxidation which makes the bloating, silicate layers and micro cracks. Using the results of these experiments, preheating characteristics and oxidation behavior were found out.