• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.557-560
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• 2003

Magnetorheological finishing(MRF) is a newly developed and recently commercialized for finishing optical components. The magnetorheological fluid consists of a water based suspension of carbonyl iron, nonmagnetic polishing abrasives, and small amounts of stabilizer. This magnetorheological fluid is pumped from conditioner on the rotating wheel and suctioned back to the conditioner, where it cooled to setpoint temperature and evaporative losses are replaced. This method could produce some problems in suction. So newly designed MRF tools is proposed in which MR fluid is not circulated and conditioned by the slurry. The new polishing mechanism is experimented. Measured surface roughness supports the validity of this mechanism.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1836-1839
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• 2003

This paper describes the surface polishing characteristics of a flat and free surface ferromagnetic substance(SM45C) that magnetic abrasive polishing processed. The effects of the various working factors on the surface roughness are clarified by experiments respectively, such as magnetic flux density. rotation speed of magnetic head. working gap, feed rate of workpiece. diameter of magnetic abrasives. and shape of workpiece. On the basis of these experiments, the polishing mechanism is discussed and the characteristics of the polishing process are described. In addition, it is found experimentally that die ＆ mold surfaces are also polished precisely by this process

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.266-272
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• 2012

This paper has aims to share fundamental knowledge for magnetic abrasive polishing and to mainly introduce recent research results. In order to enhance a magnetic flux density for nonferrous materials, advanced magnetic abrasive polishing system which is called 2nd generation system was established by electro-magnet array table, and the effectiveness of the electromagnet array table was evaluated in real polishing experiments. To increase adhesiveness of the abrasives in high speed polishing, a silicone gel agent was proposed and carbon nanotube particles as new magnetic abrasives were applied in the magnetic abrasive polishing. In addition, a strategy for optimal step-over determination by heuristic algorithm was introduced for applying large size workpiece. Curved surfaces having a uniform radius were simulated and tested with installed electro-magnet array table.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.12
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• pp.1253-1258
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• 2013

Ceramic particles as polishing abrasives are often used in a magnetic abrasive polishing process because they have strong wear resistance. Non-ferromagnetic ceramic abrasives should be mixed with ferromagnetic iron particles for controlling the mixture within a magnetic brush during the polishing process. This study describes the application of the ceramic particles for the magnetic abrasive polishing. The distribution of the magnetic abrasives attached on a tool varies with magnetic flux density and tool rotational speed. From the correlation between abrasive adhesion ratio in the tool and surface roughness produced on a workpiece, practical polishing conditions can be determined. A step-over for polishing a large sized workpiece is able to be selected by a S curve, and an ultrasonic vibration assisted MAP produces a better surface roughness and increases a polishing efficiency.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.2
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• pp.174-179
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• 2011

This paper focuses on the optimal step-over value for magnetic tool path. Since magnetic flux density is changed according to distance from center of magnetic tool. Enhanced surface roughness is also different according to change of radius. Therefore, to get a identical surface roughness on workpiece, it is necessary to find optimal tool path including step-over. In this study, response surface models for surface roughness according to change of radiuses were developed, and then optimal enhanced surface roughness for each radius was selected using genetic algorithm and simulated annealing to investigate relation between radius and surface roughness. As a result, it found that step-over value of 6.6mm is suitable for MAP of magnesium alloy.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.168-168
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• 2017

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.23-29
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• 2008

Magnetic abrasive polishing is one of the nontraditional machining technologies newly developed. But it was very difficult to cut non-magnetic materials using MAP process because the process was fundamentally possible by help of a magnetic farce. In this study, we aimed to verify analytically formation of the magnetic field in a case of the nonmagnetic materials especially focused on an aluminum alloy. And also an improving strategy of the magnetic force for the non-magnetic materials was proposed and experimentally verified. Design of experimental method was adopt for assessment of parameters' effect on the MAP results of the aluminum alloy.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.35-41
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• 2008

R/In order to satisfy the customer's variant needs for a product quality in recent years, a demand for developing higher precision machining technologies in a lot of application areas such as automobile, cellular phone and semiconductor has been increased more and more. Magnetic abrasive polishing(MAP) process is one of these precision technologies. In this study, to verify the parameters' effect of the MAP process on the surface roughness improvement of the plane and the inclined workpiece, well planned experiments which was called the design of experiments were carried out. Considered polishing factors were spindle speed, supplied current, abrasive type and working gap between the workpiece and the solid tool. As a result, it was seen that the supplied current and the working gap greatly affected the surface roughness improvement.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.316-321
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• 2011

Recently, it has been studied machining of micro parts with increasing demands for ultra precision parts. However, many engineering problems have already begun in polishing of optical parts or lens. As a method to overcome such problems, a new technology for the polishing of the target surface is being studied by controlling abrasives using MR fluids which are sensitive to magnetic fields. Since the current MR polishing system uses a big electromagnet, and is difficult to polish micro parts or spherical lens. Therefore, in this study, a round endmill type MR polishing system was developed to polish a three-dimensional structure which has spherical or inclined plane. And then, series of experiments were performed to verify the polishing performance of the developed round endmill type MR polishing system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.304-309
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• 2011

A monitoring system for magnetic abrasive polishing process is necessary to ensure the polishing products the high quality and integrity. Acoustic emission (AE) signal is known to reflect the material removal phenomena in other machining processes. In a case of the magnetic abrasive polishing of non-magnetic materials, application of AE method is very difficult because of lower machining force on the surface of workpiece and the level of AE signal is extremely lower. In this study, AE sensor-based monitoring system is applied to the magnetic abrasive polishing. The relation between the level of the AE RMS and the surface roughness during the magnetic abrasive polishing of magnesium alloy steel is investigated.