http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Magnetic Abrasive Polishing for Internal Face of STS Tube using Sludge Abrasive Grain
김희남,홍상진,Dea-Wha Soh,Byung-Woo Lee 한국전기전자재료학회 2005 Transactions on Electrical and Electronic Material Vol.6 No.3
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.
LASER BEAM 을 이용한 금속표면의 조도측정에 관한 연구
김희남,전영식,구만서 한국산업안전학회 1990 한국안전학회지 Vol.5 No.2
A new technique for the measurement of surface roughness based on the intensity fluctuations of laser light backscattered from a moving surface has been introduced. This paper reports a method of measuring surface roughness usin g coherent optics and interferometry. Included are both the theory of the technique and experimental verification. The range of surface roughness which can be accurately measured by this method is also reported.
김희남,허웅,구만서,Kim, Hee-Nam,Heo, Woong,Gu, Man-Seo 한국안전학회 1991 한국안전학회지 Vol.6 No.2
In this paper, we study effect of waveness at the optical surface roughness measurement. In generally, waveness components cause errors in calculation of the roughness value of metal surface. We study about surface roughness signals In the frequency domain for separate two signal component of real roughness and waveness by digital signal processing methods. Thereafter, determine low and high Component of frequency spectrum. By this separating frequency value we design liner low and high pass filter which cutoff frequency is 1 Hz. After this process, converted each filtered spectrum by inverse discrete fourier transformation to time domain waveness and real roughness signals We calculate surface roughness value from filtered roughness signals. For evaluate this method, we use five specimens roughness signal which obtained from optical surface roughness measuring system in 3mm/s moving speed with 0.1 mm laser beam spot size As a result, we obtain more linerized roughness value than that of unfiltered roughness signals.
김희남,윤여권,김상백,최희성,안효종 한국안전학회 2004 한국안전학회지 Vol.19 No.2
The magnetic polishing is the usefiil 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 is not spreaded widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in this 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 01.2mm 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 is found that WA and GC abrasive and sludge were strong bonding with each other by bond.