• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.45-52
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• 2000

To reduce two preprocess operations to one in the surface grinding operation the laminated grinding wheel was introduced and its availability has already been investigated in the cylindrical grinding process. Thus in this study the experiment was carried out to attempt to prove that the laminated grinding wheel can be used in the surface grinding process with respect to the roughness and grinding force.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.124-130
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• 1995

연삭작업에 있어서 요구되는 가공능률과 가공정밀도를 얻기 위해서는 적절한 결합도를 갖는 연삭숫돌을 선택하 는 것이 중요한 요건이 된다. 본 연구에서는 결합도를 평가하기 위한 일정한 기준을 설정할 목적으로 AE계측 시스템을 이용하여 대월식결합도시험방법에 따라 연삭숫돌표면의 일부를 파괴시켰을 때 발생되는 AE신호를 검출 하고 연삭숫돌의 파괴량과 AE 신호특성과의 관계 및 AE를 이용한 결합도평가의 가능성을 검토하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.7-12
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• 2019

Generally, end effectors for automatic robots can use ceramics such as alumina(Al₂O₃) and silicon carbide(SiC). In this study, black alumina was developed and used in the semiconductor field through powder molding press forming. The black alumina can be mass produced.Alumina and black alumina were ground using a plane grinder to apply to the end effector of an automatic robot. The optimal cutting conditionswere found by analyzing the surface roughness(Ra) of black alumina through grinding. The alumina surface roughness is the feed rate was about 0.72 mm/sec, and the number of revolutions was best at 0.4879 ㎛ at 1700 rpm. In addition, the black alumina surface roughness shows a precision of less than 0.2 ㎛ in most cutting conditions. The feed rate was about 0.72 mm/sec, and the number of revolutions was best at 0.1361 ㎛ at 1900 rpm. The surface roughness of black alumina was better than that of alumina by about 0.35 to 0.47 ㎛.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.63-69
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• 2003

Through the previous works, it was found that the laminated grinding wheel is more efficient to generate smoother surface in short time than general grinding wheels. But, if the laminated grinding wheel is easily worn-out, it is impossible to apply this wheel in the real grinding process, because the periodic time for dressing is closely linked to the productivity of the process. So, it is required to investigate the wear of the laminated grinding wheel fer studying the periodic time for dressing. But it is difficult to analyze the dressing period quantitavely. Therefore, in this study, periodic times for dressing of the laminated grinding wheel and general grinding wheel are deduced from the relationship between the wear of grinding wheels and the surface roughness changes according to the number of traverse in cylindrical traverse grinding through experiments. This study shows that there are some differences in the wheel wear mechanisms between the general and laminated grinding wheels. As a result, it is also found that the periodic time for dressing of the laminated grinding wheel is longer than that of the general grinding wheel.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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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.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.1
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• pp.42-51
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• 1993

Recently, WC-Co have some excellent properities as the material for the mechanical component such as metallic moulding parts, ball dies parts, and punch parts. This paper describes the surface roughness and grinding force caused by experimental study on the surface grinding of WC-Co with ultra-precision like a mirror shape using diamond wheel. Also, some investigations are carried out using WA grinding wheel to increase improved ground surface roughness such as polishing, lapping effect. Some important results obtained here are summarized as follow. 1) Within this experimental grinding condition, we can be obtained $R_{max}.\;2\mu\textrm{m}\;R_a\;0.3\mu\textrm{m}$ whichare the most favourable ground surface roughness using #140 diamond wheel, and improved surface roughness values about 20 .approx. 25% throughout 5 times sparkout grinding 2) The value of surface roughness is Rmax. $0.49\mu\textrm{m},\;R_a\;0.06\mu\textrm{m}$ using #600 diamond wheel. 3) The area of no rack zone is less than $F_{n}$ 0.27N/mm, Ft 0.009N/mm

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.5
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• pp.63-69
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• 1999

In tis study the effects of the maximum grit depth of cut on the grinding characteristics were investigated. They are AE signals produced during grinding processes have been studied to find out the appropriate AE parameters for assessing grinding processes. SM45C steel has been ground under the conditions yielding removal rate of workpiece 100, 200,300, and 400m{{{{ {m }^{3 } }}}}/min which was achieved by altering workpiece velocity(v) and apparent depth of cut(Z). According to the experimental result the value of surface roughness increases but grinding power energy rate of AE signal(AErmas2) and specific grinding energy consumed decrease as increasing the maximum grit depth of cut.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.165-171
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• 2000

To get smoother ground surface, it is required to replace the grinding wheel with a finer-grit wheel. When the operator replaces the grinding wheel, the balancing and dressing of the wheel surface are necessary. So this replacement has a lot of problems like inconvenience to operators, delays in the operation time, and ineffectiveness in the production process. Therefore, a laminated grinding wheel, which consists of three layers, is provided. The side layers are coarse grits and the middle layer is made up of fine grits. To show the effectiveness of the laminated grinding wheel, experiments on the surface roughness and the material removal rate were performed respectively. As a result, it was found that the grinding process using a laminated grinding wheel can generate smoother ground surface in shorter time.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.187-194
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• 2002

For the fine grinding process development of semiconductor monocrystalline silicon, wheel rotational speed, chuck rotational speed, feed rate and hysteresis force were controlled. Magic mirror system was used for grinding wheel pattern analysis. Curvature of wheel pattern was measured by fitting equation. The modeling of surface wheel pattern was related to wheel and chuck rotational speed. The calculated curvature of the model was well matched with the measured curvature. The statistical analysis indicated wheel and chuck rotational speed were significantly effective on.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.55-63
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• 2003

In this study, an experimental research of grinding characteristics using super-abrasives for surface carburized and heat treated SCM415 materials, which were usually used to make a linear motion guide block and were comparatively hard-to-machine materials, was carried out. In order to conduct a high efficiency and a accuracy grinding of such materials, grinding processes using CBN (Cubic boron nitride) and 38P grinding wheels have been attempted on a surface grinding machine. The grindability according to each grinding conditions was evaluated by means of a grinding force, a surface roughness and a residual stress. The experimental methods and results were presented in this paper. And also, from a proposed truing method the CBN wheels that combined a copper and a break truer gave a full scope to the wheel's performance.