Electrolytic In-process Dressing Grinding Technology Research Articles

A comparative study on state of oxide layer in ELID grinding with tool-cathode and workpiece-cathode

As a relatively new grinding technology, ELID (electrolytic in-process dressing) is widely used in some businesses. The oxide layer plays an important role in ELID grinding performance. The purpose of this work is to investigate the state of the oxide layer on ELID grinding wheel surfaces based on workpiece-cathode and tool-cathode. The thickness and surface topography of the oxide layer were measured from ELID grinding experiments based on workpiece-cathode and tool-cathode in different controlled dressing current. The normal grinding force was also compared in ELID grinding with workpiece-cathode and tool-cathode. According to the results, there are some caves on the surface of the oxide layer in ELID grinding with workpiece-cathode. With increasing controlled dressing current, the surface of the oxide layer becomes discontinuous in ELID grinding with workpiece-cathode. And the surface of the oxide layer becomes smoother with increasing controlled dressing current in ELID grinding with tool-cathode. Meanwhile, it was found that the oxide layer in ELID grinding with workpiece-cathode is thicker than that in ELID grinding with tool-cathode. Moreover, the normal grinding force in ELID grinding with workpiece-cathode is smaller than that in ELID grinding with tool-cathode. The results are helpful to improve the ELID grinding performance and apply ELID grinding technology with workpiece-cathode to abroad industrial applications.

MLCC 적층용 진공척의 자기연마와 ELID연삭을 이용한 미세버 제거 기술

This study has focused on the deburring technology of a vacuum plate for MLCC lamination using electrolytic in-process dressing (ELID) grinding, and the magnetic-assisted polishing (MAP) process. The surface of the vacuum plate has many micro-holes for vacuum suction. They are easily blocked by the burrs created in the surface-flattening process, such as the conventional grinding process. In this study, the MAP process, the ELID grinding process, and an ultrasonic vibration table are examined to remove the micro-burrs that lead to the blockage of the holes. In the results of the experiments, the MAP process and ELID grinding technology showed significant improvements of surface roughness and deburring performance.

금속기지 세라믹 복합소재의 경면연삭 가공 특성

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 μm Ra.

High efficiency ELID grinding of garnet ferrite

Hard and brittle materials such as ferrite, optical glass and ceramics have been used in many fields and still gain increasing attention. They are difficult to machine and it is hard to obtain good surface quality. Some workpieces of large batch production have large machining allowances and the machining efficiency is low with the usual grinding method. Thus it is of great importance to research the high efficiency grinding technology of hard and brittle materials. In this paper a cast iron bond diamond wheel and ELID (electrolytic in-process dressing) grinding technology are used on a surface grinder to research the high efficiency grinding technique. ELID grinding has been used previously in precision grinding with a fine abrasive wheel. In this study, the feasibility of ELID grinding for high efficiency deep-cut grinding has been researched. Garnet ferrite (YAG) has been machined both by the new method and by using a resin bond diamond wheel. The grinding force of the cast iron bond diamond wheel with ELID technology is apparently smaller than that of the other method. Under the same conditions, it is about 2/5–3/5 of the force using the resin bond diamond wheel. The result indicates that the grinding efficiency of garnet ferrite can be highly improved and good surface quality ensured by applying ELID grinding technology and adopting a large grinding depth.

Ultra-precision grinding of structural ceramics by electrolytic in-process dressing (ELID) grinding

Advanced structural ceramics, such as silicon nitride based materials, are of interest because of their unique physical and mechanical properties. However, the cost of grinding these ceramics, which is an integral part of their fabrication, is very high. The primary cost drivers in the grinding of ceramics are low efficiency due to low removal rates, high rates of wear of super-abrasive wheels, and long wheel dressing times. Ohmori, one of the present authors, has pioneered a novel grinding technology that incorporates in-process dressing of metal-bonded super-abrasive wheels, known as electrolytic in-process dressing (ELID). This technique uses a metal-bonded grinding wheel that is electrolytically dressed during the grinding process for continuous protrudent abrasive from superabrasive wheels. The principle of ELID grinding technology is addressed in this paper. Two types of silicon nitride based ceramics were ground under various conditions using ELID technology. With the application of this technology, a mirror surface finish was realized with a No. 4000 mesh-size wheel (average grain size = 4 μm). The results of these investigations are presented in this paper.

Highly Efficient Grinding of Ceramic Parts by Electrolytic In-Process Dressing (ELID) Grinding

Abstract In the manfacture of structural ceramic components, it has been well documented that the grinding costs can be as high as 90% of the total cost. Grinding costs of ceramics can be reduced by maximizing the material removal rates (MRR). A novel grinding technology that incorporates in-process dressing of metal bonded superabrasive wheels, known as Electrolytic In-Process Dressing (ELID) has been developed (1) which can significantly increase the MRR. This technique uses a metal bonded grinding wheel that is electrolytically dressed, during the grinding process, for continuous protrudent abrasive from superabrasi ve wheels. The principle of ELID grinding technology will be discussed in this paper as will its application for rough grinding. The effects of various parameters such as wheel bond type and type of power supply on the ELID grinding mechanism will also be addressed in this paper.