• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.9-16
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• 2013

The comparisons of performance characteristics between the super-mirror face grinding machine using variable air pressure developed in this laboratory to grind precisely the sliding face of a surface hardened workpiece with thermal spray and the conventional one are investigated by measuring the surface roughness and hardness for a SCM440. To process variously workpiece according to shape, size and materials, the rotating and contacting forces of the developed grinding machine can be changed by air pressure. The surface roughness of processed workpiece can be also attained to state of mirror face by grinding precisely the sliding face with changing the rotating speed of diamond wheel. It is possible to be attached to the various machine tools because the super-mirror face grinding machine using variable air pressure is a small size. The grinding efficiency is elevated because it can be worked by two or more grinding machines attached to concurrently a machine tool for the large workpiece. In this study, results show that the cusp height of the super-mirror face grinding machine for the particle size of 100 and $1500No./mm^2$ is lower than that of the conventional one because the vibration is reduced by rotating very fast the diamond wheel with a pressed air and it can be processed by rotating the diamond wheel with a constantly varied air pressure perpendicular to workpiece surface, and that the workpiece in the super-mirror face grinding machine for the particle size of $3000No./mm^2$ can be processed to state of mirror face that is rarely seen by the cusp height. It is also found that the surface hardness of both the conventional and the super-mirror face grinding machines are increased as the particle size of diamond wheel is reduced, and the surface hardness of the super-mirror face grinding machine is HRC 1.1 ~ 1.8 higher than that of the conventional one.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.5
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• pp.58-64
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• 2002

Mirror surface finish of Si-wafers has been achieved by rotary in-feed machining with cup-type wheels in ELID grinding. But the diameter of the workpiece is limited with the diameter of the grinding wheel in the in-feed machining method. In this study, some finding experiments by the rotary surface grinding machine with straight type wheels were conducted, by which the possible grinding area of the workpiece is independent of the diameter of the wheels. For the purpose of investigating the grinding characteristics of large scale diametrical silicon wafer, grinding conditions such as rotation speed of grinding wheels and revolution of workpieces are varied, and grinding machine used in this experiment is rotary type surface grinding m/c equipment with an ELID unit. The surface ground using the SD8000 wheels showed that mirror like surface roughness can be attained near 2~6 nm in Ra.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.946-949
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• 2001

Mirror surface finish of Si-wafers has been achieved by rotary in-feed machining with cup-type wheels in ELID grinding. But the diameter of the workpiece is limited with the diameter of the grinding wheel in the in-feed machining method. In this study, some grinding experiments by the rotary surface grinding machine with straight type wheels were conducted, by which the possible grinding area of the workpiece is independent of the diameter of the wheels. For the purpose of investigating the grinding characteristics of large scale diametral silicon wafer, grinding conditions such as rotation speed of grinding wheels and revolution of workpiece are varied, and grinding machine used in this experiment is rotary type surface grinding m/c equipped with an ELID unit. The surface ground using the SD8000 wheels showed that mirror like surface roughness can be attained near 2~6nm in Ra.

• Journal of the Korean Ceramic Society
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• v.49 no.1
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• pp.90-94
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• 2012

This study has been focused on properties of mirror surface grinding technology by ELID(Electrolytic In-process Dressing) for metal matrix ceramic composites using in high precision mirror for optics. The experimental studies have been carried out to get mirror surface by grinding for composites, Al-SiC, Al-graphite and Mg-SiC. Grinding process is carried out with varying abrasive mesh type, depth of cut and feed rate using diamond wheel. The machining result of the surface roughness and condition of ground surface, have been analyzed by use of surface roughness tester and SEM measurement system. ELID grinding technology could be applied successfully for the mirror-surface manufacturing processes in spite of ductility of metal matrix material. As the results of experiments, surface roughness of Al-SiC(45 wt%) has been the most superior in these experimental work-pieces as 0.021 ${\mu}m$ Ra.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.660-665
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• 2002

Mirror surface finish of Si-wafers has been achieved by rotary in-feed machining with cup-type wheels in ELID grinding. But the diameter of the workpiece is limited with the diameter of grinding wheel in the in-feed machining method. In this study, grinding experiments by the rotary surface grinding machine with straight type wheels ware conducted, by which the possible grinding area of the workpiece is independent of the diameter of the wheels. For the purpose of investigating the grinding characteristics of large scale diametrical silicon wafer, grinding conditions such as rotation speed of grinding wheels and revolution of workpieces are varied, and grinding machine used in this experiment is rotary type surface grinding n/c equipment with an ELID wit. The surface ground using the SD8000 wheels showed that mirror like surface roughness can be attained near 2 - 6 nm in Ra.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.57-60
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• 1995

Recently, ELID (electrolytic in-process dressing) grinding technique is developed. It is possible to make a efficient precision machining of hard materials such as ceramic hard metals, and quenched steels. This paper deals with some typical applications of ELID-grinding for cylindrcal machining. The significant advantages, performance and characteristics on mirror surface grinding for external surface are described.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.127-132
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• 2000

A highly efficient mirror surface grinding technology has been developed for hard and brittle materials various metal materials, by employing the ELID (electrolytic in-process dressing) grinding method using metal bonded grinding wheels. In this research, some typical applications of ELID-grinding for cylindrical grinding are introduced and the mirror grinding characteristics are investigated. Good results are obtained in the grinding of ceramics and tungsten carbide.

• 연구논문집
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• s.28
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• pp.59-71
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• 1998

The ELID(electrolytic in-process dressing) grinding method is a new precision grinding technique with the special electrolytic in-process dressing by metal bonded grinding wheel, fluid, and power supply. It is possible to make a efficient precision machining of hard and brittle materials such as ceramics, hard metals, and quenched steels by using this method, In this study, a new efficient precision grinding method with ELID was attempted for application to the machining and finishing processes of cylindrical structural components. And, we try to develop the cylindrical grinding technique for mirror surface of ceramics, tungsten carbide and SCM steel, and for the high efficiency grinding of machined parts, for example, ball screw shaft. Electrical characteristics of three different wheel grit sizes of #325, #2000 and #4000 were investigated experimentally. ELID grinding method is proved to be useful for mirror surface generation and efficient machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.231-232
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• 2007

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.247-252
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• 2012

This study has been focused on application of ELID mirror-surface grinding technology for manufacturing single crystal optic sapphire. Single crystal sapphire is a superior material with optic properties of high performance as light transmission, thermal conductivity, hardness and so on. Mirror-surface machining technology is necessary to use sapphire as optic parts. The ELID grinding system has been set up for machining of the sapphire material. According to the ELID experimental results, it shows that the surface of sapphire can be eliminated by metal bonded wheel with micron abrasives and the surface roughness of 60nmRa can be gotten using grinding wheel of 2,000 mesh in 4.5um, depth of cut. In this study, the chemical experiments after ELID grinding also has been conducted to check chemical reaction between workpiece and grinding wheel on ELID grinding process. It shows that the chemical reaction has not happened as the results of the chemical experiments.