• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.77-80
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• 2004

In this paper, we have investigated the characteristics of the magnetic abrasive using sludge on polishing of internal finishing of seamless stainless steel (STS304) tube applying magnetic abrasive polishing. Either white alumina (WA) or green carborundum (GC) grain was used to resin sludge at a low temperature, and the sludge of magnetic abrasive powder was synthesized and crushed into 200 meshes. Surface roughness was measured before and after polishing, and more than 40% of improvement of surface roughness was achieved when WA grain was used under a specific condition. Even though some degree of surface roughness due to deeper scratches still exist, but the result showed a prospective magnetic abrasive polishing using sludge with WA or GC grains.

• Transactions on Electrical and Electronic Materials
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• 제6권3호
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• pp.128-132
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• 2005

In this paper, we have investigated the characteristics of the magnetic abrasive using sludge on polishing of internal finishing of seamless stainless steel (STS304) tube applying magnetic abrasive polishing. Either white alumina (WA) or green carborundum (GC) grain was used to resin sludge at a low temperature, and the sludge of magnetic abrasive powder was synthesized and crushed into 200 meshes. Surface roughness was measured before and after polishing, and more than $40\%$ of improvement of surface roughness was achieved when WA grain was used under a specific condition. Even though some degree of surface roughness due to deeper scratches still exist, but the result showed a prospective magnetic abrasive polishing using sludge with WA or GC grains.

• 한국공작기계학회논문집
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• 제12권5호
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• pp.59-66
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• 2003

This study suggests the new ultraprecision finishing techniques for micro die and mold parts using magnetic field-assisted polishing. Conventional magnetic abrasives have several disadvantages, which are missing of abrasive particle and inequal mixture between magnetic particle and abrasive particle. Therefore, bonded magnetic abrasive particles are fabricated by several method. For example, plasma melting and direct bonding. Carbonyl iron powder is used as magnetic particle there silicon carbide and alumina are abrasive particles. Developed magnetic abrasives are analyzed using SEM. Feasibility of magnetic abrasive and polishing performance of this magnetic abrasive particles also have been investigated. After polishing, surface roughness of workpiece is reduced from 85.4 ㎚ Ra to 9 ㎚ RA.

• 동굴
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• 제82호
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• pp.8-12
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• 2007

In this paper, we have investigated the characteristics of the magnetic abrasive using sludge on polishing of internal finishing of seamless stainless steel tube applying magnetic abrasive polishing. Either green carborundum(GC) grain was used to resin sludge at a low temperature, and the sludge of magnetic abrasive powder was synthesized and crushed into 200 meshes. Surface roughness was measured before and after polishing, and more than 38% of improvement of surface roughness was achieved when grain was used under a specific condition. Even though some degree of surface roughness due to deeper scratches still exist, but the result showed a prospective magnetic abrasive polishing using sludge with green carborundum grains.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 추계학술대회 논문
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• pp.91-95
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• 1996

One must observe abrasive grain of grinding wheel and know their behaviors to understand the grinding mechanism. The behaviors of abrasive grain on the wheel surface. such as shapes distributions and changes were studied to make the grinding mechanism clear but the behaviors of abrasive grains on CBN wheel are not known enough. From this paper the working surface of a grinding wheel is observed by photography in which a picture of a wheel surface is taken by the camera through the microscope on the grinding machine and analyzed with the computer.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 추계학술대회 논문집
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• pp.134-135
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• 2007

Graphite and MoS2 were added respectively as a lubricant to improve the cutting efficiency of micro blades which contains diamond abrasive. Strength, fracture toughness, and life span of micro-blades were observed to decrease with the increase in diamond abrasive and lubricant content. Wearing mode of micro-blades and the cutting efficiency were also found to be affected by the content of diamond abrasive and the addition of lubricants.

• 한국터널지하공간학회 논문집
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• 제17권2호
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• pp.141-151
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• 2015

터널굴착의 효율성 증진 및 굴착시 발생하는 진동 저감을 위해 연마재 투입형 워터젯 시스템을 이용한 새로운 형태의 암반 굴착 방식이 개발되어 적용 중에 있다. 연마재 투입형 워터젯 시스템을 이용한 암반 굴착 방식에 있어서, 적절한 양의 연마재를 투입하는 것은 절삭 성능뿐만 아니라 전체 공정의 경제성 향상을 위해서도 매우 중요하다. 본 연구에서는, 다양한 공정 변수들 중 터널 굴착용 워터젯 시스템에서 특히 중요한 공정 변수들인 기하학적 변수(연마재 탱크(또는 호퍼) 높이, 연마재 투입관의 구배, 연마재 투입관의 길이, 연마재 투입관의 굴곡도), 연마재 변수(연마재 입자 크기), 젯 에너지 변수(수압, 유량)이 연마재 투입량 및 연마재가 믹싱 챔버 내로 흡입될 때 발생하는 흡입 압력에 미치는 영향을 규명하기 위하여 다양한 조건에서 실험을 수행하고 그 결과를 분석하였다. 또한, 실험적 연구를 통하여 연마재 투입량이 절삭 성능에 미치는 영향을 논의하였다. 본 연구 결과를 바탕으로 주요 공정 변수들을 조절하여 적절한 연마재 투입량을 유지하면 터널 굴착용 워터젯의 절삭 성능을 극대화할 수 있을 것으로 기대된다.

• 한국안전학회지
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• 제19권2호
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• pp.6-10
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• 2004

The magnetic polishing is the useful method to finish using magnetic power of magnet. This method is one of precision polishing techniques and has an aim of the clean technology using for the pure of gas and inside of the clean pipe for transportation. The magnetic abrasive polishing method is not so common for machine that it tis not spreaded widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in ths paper deals with development of the magnetic abrasive using sludge. In this development, abrasive grain WA and GC used to resin bond fabricated low temperature. And magnetic material was fabricated from the sludge which were crused into 200 mesh and average diameter ${\o}$1.2mm ball type. The XRD analysis result show that only WA and GC abrasive and sludge crystal peaks detected which explains resin bond was not any more chemical reaction. From SEM analysis it tis found that WA and GC abrasive and sludge were stron bonding with each other by bond.

• 한국재료학회지
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• 제11권10호
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• pp.907-911
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• 2001

In order to improve the grindability of magnetic abrasive, Fe-WC magnetic abrasives were made by a plasma melting method after ball milling at various times. This study aims to investigate homogeneously distributed hard phases in Fe matrix and strong bonding between the Fe-matrix and the hard phase. According to XRD, SEM and OM observation, Fe-WC magnetic abrasive powders exhibit the best grindability by plasma melting for 30h ball milling. As a result of magnetic abrasive polishing, the surface roughness, R_{max}$ 5.0$\mu\textrm{m}$, before magnetic abrasive polishing, was reduced to R_{max}$ 2.4$\mu\textrm{m}$. The new magnetic abrasive polishing process is thought to be the useful methods for the automation of three dimensional surface polishing.

• 한국안전학회지
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• 제23권5호
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• pp.43-48
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• 2008

The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision polishing techniques and has an aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are only few researchers in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper deals with development of the magnetic abrasive using Ba-Ferrite. In this development, abrasive grain GC and CBN has been made by using the resin bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Ba-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only GC, CBN and Ba-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From SEM analysis, we found that GC, CBN abrasive and Ba-Ferrite were strongly bonding with each other.