• 한국기계가공학회지
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• 제15권5호
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• pp.73-79
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• 2016

In this paper, the grinding characteristics in thrust internal grinding have been studied using vitreous CBN wheels with a machining center. Grinding experiments have been performed according to grinding conditions such as wheel feed speed, cut depth, workpiece speed, rate of grinding width and number of grinding passes. The machining error, shape of machined surfaces, grinding force, and surface roughness have been investigated though these experiments. Based on the experimental results, the grinding characteristics on the machined surface in the internal thrust grinding are discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.870-874
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• 2000

This investigation reports the grinding characteristics of titanium alloy(Ti-6Al-4V). Grinding experiments were performed at various grinding conditions and the grinding forces and specific grinding energies were measured to investigate the grindability of titanium alloy with the three different wheels including Diamond, Green carbide and Alumina. To investigate the grinding characteristics of titanium alloy grinding force, force-ratio, specific grinding energy and grinding -ratio, were measured. Surface roughness was also measured with tracer and the ground surfaces were observed with SEM. Force-ratio of grinding of titanium alloy was very lower than that of grinding of SKD-11. Specific grinding energy are almost five times larger and rougher surface was obtained in titanium grinding.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.1047-1050
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• 2002

In this paper, grinding characteristics of cylindrical plunge grinding in 200m/sec of grinding velocity was investigated by use of vitrified CBN wheel. From the experimental result, it was convinced that grinding power is decreased 2.5times and grinding efficiency is heightened 3times more according to increasing wheel velocity 80m/sec to 200m/sec And also, be expected to improvement of surface roughness and roundness by increasing the wheel velocity.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.16-21
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• 2004

As a new approach to analyze grinding energy, this paper introduces a specific grinding energy model based on the average grain. Using this model, grinding characteristics such as radial and tangential forces, specific grinding energy of SM45C were investigated altering grinding variables such as workpiece velocity(v) and apparent depth of cut(Z) in down-surface grinding. From the experimental results, there is no significant difference between the radial, tangential forces and vertical. horizontal forces because of small contact angle between wheel and workpiece. The specific grinding energy decreases as the maximum undeformed chip thickness increases. But, there is much difference between the specific grinding energies of the existing and the proposed model.

• 한국생산제조학회지
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• 제9권6호
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• pp.65-70
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• 2000

Although the net-shape molding of composites is generally recommended, molded composites frequently requires cutting or grinding due to the dimensional inaccuracy for precision machine elements. During the composite machining operations such as cutting and grinding, the temperature at the grinding area may increase beyond the allowed limit due to the low thermal conductivity of composites, which might degrade the matrix of composite. Therefore, in this work, the temperature at the grinding point during surface grinding of carbon fiber epoxy composite was measured. The grinding temperature and surface roughness were also measured to investigate the surface grinding characteristics of the composites. The experiments were performed both under dry and wet grinding conditions with respect to cutting speed, feed speed, depth of cut and stacking angle. From the experimental investigation, the optimal conditions for the composite surface grinding were suggested.

• 한국정밀공학회지
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• 제20권8호
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• pp.47-53
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• 2003

It was already proven experimentally that the laminated grinding wheel is superior to the general grinding wheel in the productivity of grinding. However, it can't be guaranteed when the workpiece material is cemented carbide. Because of its extreme hardness, the grinding wheels made up of super-abrasives are used for grinding it. So, to investigate the performance in extremely hard materials grinding using super-abrasive grinding wheels, the surface roughness characteristics of cemented carbide ground by the laminated diamond wheels are studied experimentally. Through this study, it is found that the similar surface roughness characteristics, those were found in the studies on the laminated aluminum oxide wheels, are still available.

• 한국정밀공학회지
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• 제14권6호
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• pp.44-51
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• 1997

Crinding of stainless steel, aluminium alloy, copper alloy, and titanium alloy are difficult to obtain high quality finish, because they have the mechanical properties such as low hardness, high toughness. The low hardness and the high toughness result in the loading of wheel and the poor surface finish. In order to perform the grinding operations for these sorts of materials easily, the discontinuous grinding wheel wiht multi-porous grooves has been newly developed. The multi-porous grooves inthe discontinuous grinding wheel were formed during grinding wheel manufacturing process. In this paper, discontinuous grinding wheels having intermittent ratio 0.66, 0.81 and number of grooves 18,32 have been manufactured and grinding surface characteristics of these grinding wheels for SUS304 have been analyzed. Discontinuous grinding temperature according to intermittent ratiohas been also estimated by simulation. The discontinuous grinding wheels increase the grinding performance considerably. It is desirable to use the discontinuous grinding wheel in grinding the materials with high efficiency and accuracy.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.90-94
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• 1996

Thermal problems of creep-feed grinding are more serious than regular grinding. So grinding fluid supply in creep-feed grinding is very important. Grinding fluid supply quantity is not linear with effectiveness because grinding wheel is porosity material and the grinding area is solid contact area. In this paper, by using AE signal, optimal quantity of fluid supply was determined. And surface characteristics of wet creep-feed grinding were analized.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1000-1004
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• 1995

In the case of the external cylindrical grinding machine, the grinding mechanism can cause a wheel to vibrate due to a wheel cutter. This phenomena will bring about the unsymmetric wear up to high frequency without any relation of rotational speed. So far, when the grinding spindle is analyzed, it is assumed that a wheel is considered as lumped mass at the endof a beam. Nowadays, there is a tendency to use the wheel with a lsrge diameter or CBN wheel to achieve the high speed and accuracy grinding performance. Therefore, this kind of assumption is no longer valid. At the analysis of the grinding spindle, the parameter which dapends on the dynamic characteristics is a combination force between each part. For example, there is the tightness torque of a bolt and taper element in the grindle. In addition, the material property of the wheel can contribute the dynamic characteristics. This paper shows the mode participation of the shell mode of the wheel in the grindle and the dynamic characteristics according to the parameters which are the configuration of the flange and tightness torque of a bolt and taper. Modal parameter of the wheel, flange and the spindle can be extracted through frequency response function obtained by modal test. After that, by changing the tightness torque and kinds of wheel, we could accomplish the test in the whole combined grinding spindle. To perform modal analysis of vibration characteristics in the grinding spindle, we could develop the model of finite element method.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.336-339
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• 2001

In this study an experimental investigation was conducted to find the grinding characteristics of ceramics, as compared to STDll and SUS304 materials. The grinding force and the microscopic observation of the workpieces were obtained in surface grinding. It has been found that the grinding force of ceramics is relatively low as compared to that of steels and that CBN wheel has an excellent performance.