• 한국생산제조학회지
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• 제19권2호
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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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1289-1293
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• 2005

We will improve tools performance without the change of a tools' physical shape, if we process mirror like finishing on the surface of cutting tools. Because cutting tools' shapes are very complex, the general method of polishing can't be polished. So we will apply new method of polishing which is magnetic fluid grinding technique. Magnetic fluid grinding technique can polish complex shape's workpiece by pressing the surface of workpiece with magnetic and abrasive grains in magnetic field. Therefore we developed the polishing equipment to improve the performance of cutting tools and experimented on various polishing conditions to determine the polishing conditions of cutting tools.

• 한국기계가공학회지
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• 제18권7호
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• pp.14-21
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• 2019

Large-diameter hydraulic devices such as the hydraulic reservoir in aircraft that serves to balance the hydraulic pressure in the various hydraulic devices in the cabin and to store hydraulic oil are operated by the internal piston systems. However, since this operates in an environment with high temperature and humidity, it may cause the inner surface to flake during its operation. Therefore, an anodizing surface treatment is applied to improve the corrosion resistance, abrasion resistance, and smooth operation. However, anodizing increases the surface roughness. Accordingly, the polishing process that improves the surface roughness after anodizing is important. However, the existing polishing process is performed manually, which results in an inefficient process. Therefore, in this study, we selected the optimum polishing conditions for effective polishing using the experimental design to improve the polishing process for the $Al_2O_3$ film that forms after anodization. Through experiments, we confirmed that the surface uniformity after polishing was superior as the feed rate was slower when the same polishing time had been applied.

• 한국생산제조학회지
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• 제21권2호
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• pp.246-251
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• 2012

Pulse electrochemical polishing process has been used to improve mechanical properties such as surface roughness and corrosion resistance on conductive metallic materials. In addition, pulse electrochemical polishing process with various frequency may produce a lustrous, smoother, deburred and cleaned surface on workpiece. The aim of this paper is to study surface characteristics of pulse electrochemical polishing for various frequency conditions using AFM to verify localized surface variation in nanometer scale.

• 한국공작기계학회논문집
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• 제15권1호
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• pp.119-126
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• 2006

The finishing process of die requires the processing technique of a height efficiency and precision. Because the precision of die gives the quality of goods the influence directly. The hydro-static polishing device employs the hydro-static axis and is able to polish the structure of complex picture under the constant pressure and is got constant surface roughness at all polished plane. Therefore, In order to polish precision sculptured surface, it was used the hydro-static polishing device. Polishing device's polishing characteristic is estimated by polishing conditions which are size of abrasive, material of tools. And, because the surface quality of workpiece depends on polishing pattern which relates to motion of abrasive grain. The polishing characteristic according to polishing pattern was evaluated.

• 소성∙가공
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• 제24권6호
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• pp.431-436
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• 2015

MR fluid can change viscosity in the presence of a magnetic field. A characteristic of MR fluid is reduced scattering during jetting. For these reasons a MR fluid jet polishing system can be used for ultra-precision polishing. In the current paper, the polishing path was calculated considering the aspherical lens profile equation and the experimental conditions for the MR fluid jet polishing system. Then the polishing of an aspherical lens mold core using the MR fluid jet polishing system with the calculated path control was made and the results were compared before and after polishing.

• 한국공작기계학회논문집
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• 제15권1호
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• pp.32-38
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• 2006

The magnetic fluid polishing technique can polish the tool of complex shape, because the polishing method which polishes as compress the workpiece by the magnetism abrasives to arrange to the linear according to the line of magnetic force. Therefore, we producted the magnetic fluid polishing device in order that mirror like finishing processes the tool surface. In order to a polishing condition selection, polishing characteristic was estimated by polishing conditions which are magnetic flux density, polishing speed, grain size, magnetic fluid. The tool was polished to the selected polishing condition. The result to evaluate the polished tool's performance with the cutting force and tool wear, the polished tool's performance was improved compared with the tool not to polish.

• 한국기계가공학회지
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• 제12권2호
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• pp.100-106
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• 2013

Stainless steel has some excellent properties as the material for the mechanical component. Purpose of this study is carried out to obtain mirror surface on the surperfinishing of stainless steel with high efficiency. To achieve this, we have conducted a series of polishing experiment for stainless steel using abrasive film from the perspective of oscillation speed, the rotational speed of workpiece, contact roller hardness, contact pressure and feed rate. Abrasive film used this study is a micro-finishing film and a lapping film. Furthermore, the polishing characteristics and efficiency of stainless steel is discussed through measuring optimal polishing time and surface roughness. From the obtained results, it was confirmed that efficient superfinishing conditions and polishing characteristic of Stainless steel can be determined.

• 한국정밀공학회지
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• 제30권12호
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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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.519-523
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• 1996

The polishing tool unit is developed which can be attached on the machining center and automatic polishing system for die and mold is also established. So, experiments are carried out under the several polishing conditions. The polishing properties of automatic polishing operation such as surface roughness, stock removal and maximum profile valley depth are obtained and analyzed quantitatively for each polishing tool. The purpose of this study is to construct an expert system for optimal condition of die and mold automatic polishing using the knowledge base that is obtained in the polishing experiments and, to verify the feasibility of the expert system through the experiments. Using this expert system, unskilled operators will be able to obtain the knowledge and experience of an expert.