• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.48-52
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• 1995

Chipping is an unavidable phenomean in the slot grinding process of hard and brittle materials. However,it should be reduced for the improvement of surface integrity in the manufacture of optical and semiconductor components. Electrolytic In-process Dressing (ELID) technique for metal bonded superabrasive grinding wheel has been developed for mirror surface grinding of hard and brittle materials. Electrically dressed wheel surface has sharply exposed abrasives and results in lower grinding force, higher grinding efficiency in grinding. The paper deals with a newly developed method for slot grinding using ELID and was implemented to improve grooved surface quality and decreases chipping size on the edge of the groove. As a result, we accomplished shipping-free grooves and obtained the clear ground sufaces on glass and tungsten carbide.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.18-25
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• 1999

Chipping is an unavoidable phenomenon in the slot grinding process of hard and brittle materials. However, it should be reduced for the improvement of surface integrity in the manufacture of optical and semiconductor components. Electrolytic In-process Dressing (ELID) technique for metal bonded superabrasive grinding wheel has been developed for mirror surface grinding of hard and brittle materials. Electrically dressed wheel surface has sharply exposed abrasives and results in lower grinding force, higher grinding efficiency in grinding. The paper deals with a newly developed method for slot grinding using ELID and was implemented to improve grooved surface quality and decreases chipping size on the edge of the groove. As a result, we accomplished chipping-free grooves and obtained the clear ground surfaces on glass and WC.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.106-113
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• 2000

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 optics, electronics and semiconductor parts. Slot grinding is very efficient for the generation of micro ordered groove with hard and brittle materials. In the process of slot grinding, chipping at the sharp edges and microcracks of the ground grooves are inevitable defects. Chipping should be reduced for the improvement of surface integrity. Mechanical contact with diamond grits causes microcracks at the grooves. This damage resides subsurface, and can be the cause of failure of the punch die. This paper deals with chipping generation at the sharp edges, surface integrity of side groove and fracture strength is related to the microcracks in the slot grinding.

• 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.

• Cement Symposium
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• no.1
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• pp.50-55
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• 1973

Improvement of grinding efficiency about open circuit grinding mill in cement production was investigated and the results were as follows; 1. Controlled the steel ball by charging ratio. 2. Raised the slot ratio from 3$\%$ to 4.5$\%$

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.52-59
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• 1999

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

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.109-117
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• 2003

With development of high advanced technologies and skills, micro machining techniques also are being more functional and smaller. Some of the recently developed micro machining technologies are micro drilling, micro EDM, WEDG, LBM, micro milling, micro UVM etc. In these micro machining techniques, Micro -EDM is generally used for machining micro holes, pockets, and micro structures in difficult-cut-materials. For machining micro structures, first of all, tool electrode should be fabricated by WEDG process. In micro-EDM, parameters such as peak current, pulse width, duration time are very important to fabricate the tool electrode and micro structures. Developed experimental equipments are composed of RLC circuit with PWM. In this paper, using developed micro EDM machine, the characteristics of micro electro discharge machining are investigated at micro holes, slot, and pocket machining etc. Also the trends of tool wear are investigated in case of hole and slot machining.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.2
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• pp.5-11
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• 2005

Among the micro machining techniques, micro EDM is generally used for machining micro holes, pockets, and micro structures on difficult-cut-materials. Micro EDM parameters such as applied voltage, capacitance, peak current, pulse width, duration time are very important to fabricate the tool electrode and produce the micro structures. Developed micro EDM machine is composed of a 3-axis driving system and RC circuit equipped with pulse generator. In this paper, using micro EDM machine, the characteristics of micro EDM process are investigated and it is applied to micro holes, slots, and pockets machining. Through experiments, relations between machined surface and voltages and between MRR and feedrate are investigated. Also the trends of tool wear are investigated in case of hole and slot machining.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.123-129
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• 2022

Quartz (SiO2) has high abrasion and heat resistances and excellent chemical and mechanical properties; therefore, it is used in various industries, such as machinery, chemistry, optics, and medicine. Quartz is a high-hardness and brittle material and is classified as the topmost difficult-to-cut material, which is because of the cracking or chipping at the edge during processing. Corner wear, such as cracks and chippings that occur during cutting, is a major cause for the deterioration in the machining quality. Therefore, many researchers are investigating various techniques to process quartz effectively. However, owing to the mechanical properties of quartz, most studies have been conducted on grinding, micromachining, and microdrilling. Few studies have been conducted on quartz processing. The purpose of this study was to analyze the machining characteristics according to the machining factors during the slot machining of quartz using a cubic boron nitride (CBN) tool and to select the optimal machining conditions using the Taguchi method. The machining experiment was performed considering three process variables: the spindle speed, feed rate, and depth of cut. The cutting force and surface roughness were analyzed according to the processing conditions.