• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1499-1505
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• 2010

In general, magnetic abrasive polishing can be used to effectively produce a mirror-like surface; however, industrial applications of this process involve some unsolved problems. For example, the polishing efficiency is low, and the used abrasives have to be treated. In this study, which is aimed at solving these problems, a novel medium of silicone gel, consisting of ferromagnetic particles and abrasives, is developed, and the effect of this medium is assessed on the basis of Taguchi's experimental method. The workpiece is a tungsten carbide steel and the surface roughness after magnetic abrasive polishing using the silicone gel is evaluated.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.37-43
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• 2004

The performance of magnetic abrasive finishing fur surface is evaluated by the characteristic curve. The characteristic curve is generated by experiment in surface finishing. For experiment, new magnetic inductor is designed and manufactured. 15 kinds of powders are provided to find the relationship between powder characteristic and finishing performance. As powder, Fe-TiC. Polymer-TiC and Fe-NbC are used with different size. The size of abrasives and location are also important factor for the performance. From characteristic curve, two index are obtained, which specify the initial finishing performance and endurance of finishing performance. It is proved that the performance index can be applied to select proper powder for efficient deburring. It is shown that the characteristic curve can be used as good tools for evaluating powder performance in surface finishing and deburring.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.11
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• pp.2786-2795
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• 2000

Recently, the technology for internal polishing is needed for ultra-clean machining for the prevention of corrosion and pollution of parts is the area of high technology industries such as semiconductor, electronics, telecommunication optics, aerospace, and motors. In this study, an internal polishing system using the magnetic force was developed for the production of ultra-clean tubes with averaged surface roughness ranging from 0.2㎛ to 0.05㎛ or less, and magnetic abrasives composed of WC/Co powder were developed, After finding the optimal condition on each, machining characteristics using newly developed abrasive were analyzed. Form the results obtained by experimental design method, the optimal polishing condition was analyzed and, thhereafter internal polishing was done.

• Korean Journal of Materials Research
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• v.11 no.10
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• pp.907-911
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• 2001

In order to improve the grindability of magnetic abrasive, Fe-WC magnetic abrasives were made by a plasma melting method after ball milling at various times. This study aims to investigate homogeneously distributed hard phases in Fe matrix and strong bonding between the Fe-matrix and the hard phase. According to XRD, SEM and OM observation, Fe-WC magnetic abrasive powders exhibit the best grindability by plasma melting for 30h ball milling. As a result of magnetic abrasive polishing, the surface roughness, R_{max}$ 5.0$\mu\textrm{m}$, before magnetic abrasive polishing, was reduced to R_{max}$ 2.4$\mu\textrm{m}$. The new magnetic abrasive polishing process is thought to be the useful methods for the automation of three dimensional surface polishing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.960-963
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• 2001

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 vibrated and a workpiece is rotated only is tried in a non-ferromagnetic pipe(SUS304), and its finishing characteristics is experimental results, it is found that the vibration effects of magnetic poles on the finishing characteristics are large in internal finishing.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.1
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• pp.22-28
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• 2009

In order to optimize the polishing process, Run to Run control scheme has been applied to the micro mold polishing in this study. Also, to fully understand the effect of parameters on the surface roughness a design of experiment is performed. By linear approximation of main factors such as gap and rotational speed of micro quill, EWMA (Exponential Weighted Moving Average) gradual mode controller is adopted as a optimizing tool. Consequently, the process converged quickly at a target value of surface roughness Ra 10nm and Rmax 50nm, and was hardly affected by unwanted process noises like initial surface quality and wear of magnetic abrasives.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.371-372
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• 2008

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.2
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• pp.184-190
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• 2010

Recently, the polishing process using magnetorheological fluids(MR fluids) has been focused as a new ultra-precision polishing technology for micro and optical parts such as aspheric lenses, etc. This method uses MR fluid as a polishing media which contains required micro abrasives. In the MR polishing process, the surface roughness and material removal rate of a workpiece are affected by the process parameters, such as the properties of used nonmagnetic abrasives(particle material, size, aspect ratio and density, etc.), rotating wheel speed, imposed magnetic flux density and feed rate, etc. The objective of this research is to predict MRR according to the polishing conditions based on the multiple regression analysis. Three polishing parameters such as wheel speed, feed rates and current value were optimized. For experimental works, an orthogonal array L27(313) was used based on DOE(Design of Experiments), and ANOVA(Analysis of Variance) was carried out. Finally, it was possible to recognize that the sequence of the factors affecting MRR correspond to feed rate, current and wheel speed, and to determine a combination of optimal polishing conditions.

• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.13-19
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• 2011

The magnetic polishing is the useful method to finish using magnetic power of magnet. That method is one of precision polishing techniques and has an aim of the clean technology using for the pure of gas and inside of the clean pipe. The magnetic abrasive polishing method is not so common for machine that it is not spreaded widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper deals with development of the magnetic abrasive using Sr-Ferrite. In this development, abrasive grain GC used to resin bond fabricated low temperature. And Sr-Ferrite of magnetic abrasive powder fabricated that Sr-Ferrite was crused into 200 mesh. The XRD analysis result show that only GC abrasive and Sr-Ferrite crystal peaks detected which explains resin bond was not any more chemical reaction. From SEM analysis it is found that GC abrasive and Sr-Ferrite were strong bonding with each other by bond. The magnetic polishing is performed by polishing the surface of pipe by attracting magnetic abrasives with magnetic fields. This can be widely applied for finishing machinery fabrications such as various pipes and for other safety processes. In this paper, we could have investigated in to the changes of the movement of magnetic abrasive grain. In reference to this result, we could have made the experiment which is set under the condition of the magnetic flux density, polishing velocity according to the form of magnetic brush.

• Journal of the Korean Magnetics Society
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• v.6 no.1
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• pp.28-35
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• 1996

Dispersion behavior was investigated as functions of species and arrount of addtives, binders, abrasives, lubricants, etc.. Dispersibilityand other various properties were affected by the fuctional groups of binders. Friction coefficient and surface roughness of tape were changed with lubricants, therefore duratility of magnetic tape was varied. As a result of above investigations, we concluded that dispersion behavior of particles was very sensitive for obtaining maximum properties of metal particle tape.