• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1015-1016
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• 2012

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.179-185
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• 2004

Surface finish technology is highly demanded in the wide field of industry applications from ultra-precision parts to rough casting parts. Therefore, many kinds of surface finish technologies have been developed for each purpose. Because surface of a car's wheel cast is very rough it becomes the reason of the corrosion. This surface is coated to complement such problem but because surface is rough, the result of coating is not good and the coated metal peels off well. Therefore before the wheel is coated, it is necessary to grind the surface. In this study, we devised the plant to apply a barrel machining to improve the surface roughness and enhance the productivity. Also we could obtain the optimum barrel machining conditions for the proper surface roughness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.444-449
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• 1996

The semiconductor, which is precision product, requires many inspection processes. The surface conditions of the semiconductor chip affect on the functions of the semiconductors. The defects of the chip surface are cracks or voids. As general inspection method requires many inspection procedure, the inspection system which searches immediately and precisely the defects of the semiconductor chip surface is required. We suggest the detection algorithm for inspecting the surface defects of the semiconductor surface. The proposed algorithm first regards the semiconductor surface as random texture and point spread function, and secondly presents the character of texture by linear estimation theorem. This paper assumes that the gray level of each pixel of an image is estimated from a weighted sum of gray levels of its neighbor pixels by linear estimation theorem. The weight coefficients are determined so that the mean square error is minimized. The obtained estimation window(two-dimensional estimation window) characterizes the surface texture of semiconductor and is used to discriminate the defects of semiconductor surface.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.4
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• pp.15-23
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• 2002

With the development of a laser scanner of high precision and increased speed, reverse engineering becomes a key approach to reduce the time for the development of new products. But the modeling process is not so automated enough until now. Modeling in real workshops is usually performed by the experienced operators and it requires a skillful technique to get the resultant surface of high quality and precision. In this paper, a systematic solution is proposed to automate the free-form surface generation from the measured point data. Compatibility is imposed to the measured point data during input curve generation. And the compatibility of cross-sectional curve is also considered for the loft surface generation. The data in each step is produced in IGES file format to make an easy interface to other CAD/CAM software without any further data manipulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1109-1112
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• 2001

In the grinding process, the edge of shape is very important to evaluate the surface roughness and the precision of dimension. To keep precision of product, parameters with respect to the amount of wheel wear have to limit by grinding condition. In this paper, we measured variation of grinding force to seek the grinding characteristics by the amount of wheel wear in surface grinding. Also, we find out that how these condition give influence to wheel life.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1873-1876
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• 2003

Magneto-rheological polishing is a new technology used in precision polishing. It utilizes magneto-rheological fluid. nonmagnetic polishing abrasive, aqueous carrier fluids in magnetic field to remove material from a part surface. Silicon micro channel as work piece is fixed in the slurry which is made of MR fluid and CeO$_2$(10 vol%) abrasive particles. And permanent magnet rotate in the slurry to transfers magnetic force to abrasive particles by increasing yield strength of MR fluid. so, the obtained bottom surface roughness of micro channel by experiment reduced to Ra 0.010 $\mu\textrm{m}$ Rmax 0.103 $\mu\textrm{m}$ and finwall surface roughness of micro channel reduced to Ra 0.018 $\mu\textrm{m}$ Rmax 0.468 $\mu\textrm{m}$. At optimum conditions of variables, the workpiece as silicon micro channel have about 24 times smaller surface roughness than before polishing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.125-128
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• 1997

They use a Ball End-mill in order to manufacturing sculptured surface when making metal mold, mold, cars and aircraft. In the work of a Ball End-mill case, customers do not often satisfied with manufacturing precision. Eventually, they have to re-work for the purpose of meeting manufacturing precision. There are resulted in lots of loss, whereby, in terms of both time and costs. The reasons of tolerance reducing manufacturing precision are thermal strain, the surface is damaged because of increasing cutting force and tool wear, tool deflection etc.. We focus on, however, manufacturing precision caused due to deflection of tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.77-78
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• 2009

• Journal of the Korean Society for Precision Engineering
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• v.5 no.3
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• pp.91-100
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• 1988

Surface rolling which is one of the plastic deformation have advantages to imporve surface roughness, hardness and fatigue strength with relatively simple processes. In this study, the effect of previous cutting process before rolling on the surface roughness in surface rolling for mild steel was investigated. The results obtained are as follows. (1) Waveness of the previous process has the effect on the precision of the works and coarse waveness resulted in less improvement of the surface roughness. (2) The reduction of diameter and increase of hardness can be obtained at the first rolling process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.397-401
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• 2003

In this work, diamond turning process is used to produce mirror surface on a Al cone. The Al cone as used as a mirror which can reflect a laser beam without scattering and, hence, it is critical to minimize the surface roughness of a Al cone. During diamond turning, feedrate and tool nose radius are changed to investigate characteristics of the ultra precision machined surface of a Al cone. A laser beam of 633 nm is applied to examine the effect of surface roughness on the characteristics of reflectivity. It is found that surface roughness is not significantly affected by feedrate. The main factor influencing surface roughness is tool nose radius. The line patterns of reflected laser beams show that the minimum surface roughness of 0.08 $\mu\textrm{m}$ (Ra) is required to avoid scattering phenomena of reflectivity.