• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.964-967
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• 2002

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, another method of magnetic abrasive machining in which the N and S magnetic poles are feed and a workpiece is rotated only is tried in a fine-pipe, and its finishing characteristics is experimently investigated by various effective factors such as feeding amplitude. From the experimental results, it is found that the feed effects of magnetic poles on the finishing characteristics are large in internal finishing.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.47-53
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• 2001

Results ar presented of a new process for internal precision finishing of slender fine ceramic pipes using a magnetic field generated by a permanent magnets. For finishing the interior surface of a long pipe, a new type of finishing equipment was developed which can be very easily used in an industrial surrounding. In general, the pipe is so slender that a conventional finishing tool is hardly inserted into the pipe deeply, being impossible to finish. Therefore, a new technology has been considered to finish inside of a slender ceramic pipe by a simple technique. In this experimental, Magnetic Abrasive Machining is applied for the inner surface of silicon nitride fine ceramic pipe using ferromagnetic particles mixed with chromium-oxide powder. It is shown the initial roughness of 2.6㎛ Ry(0.42㎛ Ra) in the inside surface can be precisely finished to the roughness of 0.1㎛ Ry(0.01㎛ Ra). This paper discusses the outline of the processing by the application of magnetic abrasive machining and a few finishing characteristics.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.1
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• pp.13-18
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• 2006

The magnetic abrasive machining has been developed as a new finishing technology to obtain a fine surface of workpiece. In this paper, a static magnetic field method and a magnetic abrasive brush which has many technical advantages, are applied for the magnetic abrasive machining. In the experiment, some items such as finishing time, ratio of the magnetic abrasives to Fe-powder, motor revolutions per minute, and motor ratio revolutions per minute are tested. The results of this study have shown the fact that the burr height is mostly affected by the finishing time and the abrasive ratio. Also, it has been found that the magnetic abrasive machining is a possible new technology for the deburring.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.38-44
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• 2004

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 non-ferromagnetic pipe. In this paper, an abrasive slurry circulation system was designed and manufactured. As a result, it was found that a fine inner surface of pipe was available by the use of these machining methods. The basic machining characteristics of pin-type magnetic tools were analyzed experimentally. In addition, the experimental results show that pin-type magnetic tools have more machining efficiency than Iron particles as magnetic tools.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.109-117
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• 2005

In case of fine machining processes, the cutting state monitoring by a skilled operator is impossible because the physical changes generated during fine machining are very weak. To realize the high efficient and precise fine machining, it is necessary to develop the sensor based monitoring system which is able to detect the fine changes of cutting state. In this paper, the fine acoustic emission monitoring system is developed to monitor the state of the fine machining process. The developed system consists of the AE sensor and the AE signal processing unit. And this has the high-sensitivity and bandwidth which can detect fine AE signal generated during fine machining process. In order to investigate the feasibility of the developed system, evaluation experiments were performed in the fine fixed-abrasive machining processes such as polishing and glass ferrule slicing. Experimental results show that the developed monitoring system possesses an excellent real-time monitoring capability at fine machining processes.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.10
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• pp.178-183
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• 2001

Abrasive jet machining(AJM) process is similar to the sand blasting and effectively removes hard and brittle materials. AJM has applied to rough working such as debarring and rough finishing. As the need for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro AJM is developed, and has become the inevitable technique to micromachining. This paper describes the performance of the micro AJM in micro grooving of glass. Diameter of hole and width of line in grooving is 80${\mu}{\textrm}{m}$. Experimental results showed good performance in micro grooving of glass, but the size of machined groove increased about 2~4${\mu}{\textrm}{m}$. With the fine tuning of masking process and compensation of film wear. this micro AJM could be effectively applied to the micro machining of semiconductor, electronic devices and LCD.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.227-230
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• 2002

New polishing technique for small parts has been tried out using the principle of particle electromechanics. Common fine abrasives such as alumina, diamond, silicon carbide are dielectric materials which are polarized under an electric field, and a non-uniform electric field makes abrasive particles translate along the field line. Using this principle, We make abrasive particles aggregate in the vicinity of the micro tool which is fir the surface finishing of a small part without contact with it. The behavior of particles is optically measured, and the machined depth of glass is examined.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.34-41
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• 2004

A new method to fabricate the fine magnetic abrasives by using mechanical alloying is proposed. The mechanical alloying process is a solid powder process where the powder particles are subjected to high energetic impact by the balls in a vial. As the powder particles in the vial are continuously impacted by the balls, cold welding between particles and fracturing of the particles take place repeatedly during the ball milling process using a planetary mill. After the manufacturing process, fine magnetic abrasives which the guest abrasive particles c lung to the base metal matrix without bonding material can be obtained. The shape of the newly fabricated fine magnetic abrasives was investigated using SEM and its polishing performance was verified by experiment. It is very helpful to finishing the injection mold steel in final polishing stage. The areal ms surface roughness of the workpiece after several polishing processes has decreased to a few nanometer scales.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.1
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• pp.7-12
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• 2005

An internal finishing process by the application of magnetic abrasive finishing has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, another method of magnetic abrasive machining in which the N and S magnetic poles are vibrated and a workpiece is rotated only is tried in a non-ferromagnetic pipe(SUS304), and its finishing characteristics is experimently investigated by various effective factors such as vibrating frequency and amplitude. From the experimental results, it is found that the vibration effects of magnetic poles on the finishing characteristics are large in internal finishing.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.95-101
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• 2011

Micro-abrasive jet machining(${\mu}AJM$) using mask is a fine machining technology which can carve a figure on a material. The mask should have holes exactly same as the required figure. Abrasive particles are jetted into the holes of the mask and it collide with the material. The collision break off small portion of the material. And the ${\mu}AJM$ nozzle should move all over the machining area. However, in general the carving shape is modeled as in a bitmap figure, because it often contains characters. And the mask model is also often modeled from the bitmap image. Therefore, the machining path of the ${\mu}AJM$ also efficient if it can be generated from the bitmap image. This paper suggest an algorithm which can generate ${\mu}AJM$ tool path directly from the bitmap image of the carving figure. And shows some test results and applications.