• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.142-148
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• 1993

Recectly, development of expert system utilizing the domain specific knowledge focuses upon the machining operations. This paper describes an expert system for selecting the optimum grinding wheel based on the Analytic Hierarchy Process and Fuzzy Logic. Knowledge-base, in this system, for selecting of grinding wheel is designed to appling the knowhow and experience knowledge of skilled hands. In this paper, firstly determination method of fuzzy membership function utilizing the qualitative knowledge, and then selection of the optimum wheel from among the available components according to Saaty's priority rule are described. Lastly,some implementation results are suggested.

• Journal of Korea Foundry Society
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• v.12 no.4
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• pp.317-325
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• 1992

Diamond is the hardest material known to humans, also possesses the highest thermal conductivity and a very low thermal expansion coefficient. Therefore, these properties of diamond make them logical choices for many difficult grinding application. Bonding material is a very important factor to performance of a grinding wheel. Grinding glass constitutes one of the major application areas of diamond grinding wheels, and Cu-Sn tin bronze matrix is widely used as a metal bond of diamond wheel in grinding glass but these studies are rarely reported. The bronze test pieces excluding diamond are sintered by the method of hot sizing respectively at $600^{\circ}C$, $650^{\circ}C$, $700^{\circ}C$, with a composition(Cu-10wt%Sn) on ${\alpha}$ phase and two compositions(Cu-20wt%Sn and Cu-23wt%Sn) on ${\alpha}+{\beta}$ phase. The rupture strength of Cu-10wt%Sn is highest. The bronze bonded diamond wheels are manufactured by same conditions as the bronze test pieces. The results of grinding ratio of wheels are highest in case of Cu-10wt%Sn bonded wheel sintered at $650^{\circ}C$ and grinding power is highest in same composition sintered at $700^{\circ}C$.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.6
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• pp.485-490
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• 2016

This study focused on developing an electro-discharge truing method for the ELID grinding process using a metal-bonded grinding wheel. The truing process in grinding plays important roles in enhancing the quality of the ground surface. In this study, a reference current in the electro-discharge truing process was confirmed to be a viable solution for efficient truing through performance experiments. Current and voltage variation experiments were carried out and the variation output data were collected with a monitoring program to understand the electrodischarge phenomenon that occurs between metal-bonded grinding wheels and copper electrodes. The experimental results showed that as the reference current decreased, the average electro-discharge energy decreased. Therefore, the reference current can be used as an indicator to estimate the size of the gap between the truer and grinding wheel.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.68-74
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• 1999

One of the recent changes in machining technology is rapid application of micro- and high precision grinding processes. A fine groove generation is necessary for the fabrication of optic, electronic and semiconductor parts, and achieved by chemical or mechanical processes. Slot grinding is very efficient for the generation of micro ordered groove with hard and brittle materials. As slot grinding is continuous, the ground depth become gradually shallow because of wheel wear. The form accuracy become worse from the increase of ground slot width by the loading phenomena at wheel side, results on chipping damage of the workpiece. The experiments achieve to the enhancement of the form accuracy and chipping free of the brittle materials using V shaped cast iron bonded diamond wheels. In this study we focused on the investigation of the effect of the high pressure air jet on the grinding characteristics. As a results, we found that the high pressure air jet is very effective on the reductions of the wheel wear, enhancement of the form accuracy.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.25-30
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• 1997

In recent years, grinding techniques for precision machining of astainless steel used in shaft, screw parts and clear value have been improved by using superabrasive wheel and precision grinding machine. The completion of optimum dressing of superabrasive wheel makes possible the effective percision grinding of stainless steel. However, the present dressing system cannot have control of optimum dressing of the superabrabive wheel. In this study, a new system and the grinding mechanism of optimum in-process electrolytic dressing were proposed. This system can carry out optimum in-process dressing of superabrasive wheel. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of stainless steel(SUS304).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.832-836
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• 1997

An experimental study on the grinding temperature, surface roughness and Acoustic Emission(AE) signal was conducted with different shapes of wheel. The grinding characteristics by slotted shapes of wheel changed by width and helical angle,were compared with those by general one. Lower grinding temperature was obtained for 30 .deg. helical angel with 10mm width and Root Mean Square(RMS) values of AE signals were lower for slotted shapes rather than general one. Surface roughness characteristic of slotted shapes found to be rough,but the value of roughness for 45 .deg. helical angel with 6mm width, represented to similar tendency general one.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1020-1024
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• 1997

Recently the use of ceramic materals has been greatly increased in the industries. But machining of the ceramics is quite unproductive because of their high stength,high hardness,and brittleness. The efficiency of the grinding operation of ceramics depends on the preparation of diamond grinding wheel, i.e.,truning and dressing. This paper describes some experimental results on the dressing conditions of diamond grinding wheel. The dressing performance is evaluated by the magnitude of normal grinding force. The better dressed wheels result in the lower normal grinding forces. The dressing performances of copper plate and aluminum oxide dressing stick are compared. The optimum dressing conditions including the grit size of dressing sticks, the depth of the dressing operation, and the dressing speed qre determined.

• Composites Research
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• v.13 no.5
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• pp.44-49
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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. The surface roughness and cutting force were also measured to investigate the surface grinding characteristics of the composites using the vitrified bonded wheel (WA, GC). The experiments were performed dry grinding conditions with respect to cutting speed, feed speed, depth of cut of the stacking sequence $[O]_{nT.}$ From the experimental investigation, the optimal conditions both the vitrified bonded wheel WA and GC for the surface grinding are suggested.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.165-170
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• 2012

The resin bonded diamond wheel is used to grind the difficult-to-cut materials. Traditionally, the resin bonded diamond wheel is manufactured without any pores due to the characteristics of resin bond. In this study, two porous resin bonded diamond wheel were made and the grinding characteristics were compared with traditional nonporous ones. The experimental results indicate that the porous resin bond diamond wheel require less grinding forces and powers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.32-36
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• 2002

This paper presents the structural characteristic analysis of a centerless grinding machine with concrete bed. The centerless grinding machine is composed of grinding wheel head, regulating wheel head, concrete bed, wheel dresser and so on. Especially, the concrete bed is introduced to improve the static, dynamic and thermal characteristics of the centerless grinding machine. The structural analysis model of centerless grinding machine is constructed by the finite element method, and the structural characteristics in the design stage are estimated based on the structural deformation and harmonic response under the various testing conditions related to gravity force and directional farces