http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
유기변성 하이브리드 세라믹 물질을 결합제로 이용한 고체피막윤활제의 마찰마모 특성
한흥구(Hung-Gu Han),공호성(Hosung Kong),윤의성(Eui-Sung Yoon) 한국트라이볼로지학회 2003 한국트라이볼로지학회 학술대회 Vol.36 No.-
In order to enhance the thermal stability of binder materials of bonded type solid lubricants, several metal-alkoxide based sol-gel materials such as methy ltrimethoxysilane(MTMOS), titaniumisopropoxide(Ti(Opr<SUP>i</SUP>)₄), zirconiumisopropoxide (Zr(Opr<SUP>j</SUP>)₄) and aluminumbutoxide(Al(Obu<SUP>t</SUP>)₄) were modified chemically by both epoxy and acrylic silane compounds. Friction and wear characteristics of the bonded solid lubricants, whose binders were of several hybrid ceramic materials, were tested with a reciprocating tribo-tester. Wear life was evaluated with respect to the heat-curing temperature, friction temperature, type of supplement lubricants, and ratio of binder materials. Test results showed that the Si-Zr hybrid ceramic materials modified by epoxy-silane compounds had a higher wear life compared to others. Sb₂O₃ was the most effective supplement lubricants in the high temperature, and XPS analyses revealed that it was caused mainly by a strong anti-oxidation effect to MoS₂ particles. The higher heat-curing temperature resulted in the higher wear life, and the higher friction temperature resulted in the lower wear life.
졸-겔 공정에 의한 유기변성 하이브리드 세라믹 물질의 미세 마찰마모 특성
한흥구(Hung-Gu Han),공호성(Hosung Kong),윤의성(Eui-Sung Yoon),양승호(Seung-Ho Yang) 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.35 No.-
In order to enhance the thermal stability of binder materials of bonded type solid lubricants, several combinations of metal-alkoxide based sol-gel materials such as methyltrimethoxysilane(MTMOS), titaniumisopropoxide(Ti(Opr<SUP>i</SUP>)₄), zirconiumisopropoxide(Zr(Obu<SUP>i</SUP>)₄) and aluminumbutoxide(Al(Obu<SUP>t</SUP>)₄) were chemically modified by epoxy-, acrylic- and fluoro-silane compounds, respectively, in this work. Friction and wear characteristics of these hybrid ceramic materials were tested with a micro tribo-tester where a reciprocating steel ball slid on a test material, and the tribological property was also evaluated with respect to both heat-curing temperature and the time. Test results generally showed that hybrid ceramic materials modified by epoxy-silane compounds had a low friction compared to others. And the higher heat-curing temperature and the longer heat treatment time resulted in the higher friction and the lower wear. IR spectroscopic analyses revealed that it was caused mainly by the increased metal oxide content in hybrid ceramics when the heat-curing temperature was over 320℃.
성인하(In-Ha Sung),한흥구(Hung-Gu Han),공호성(Hongsung Kong) 한국트라이볼로지학회 2008 한국트라이볼로지학회 학술대회 Vol.2008 No.11
An experimental investigation of the frictional behavior between nano- and micro-scale tips and various surfaces were performed using atomic force microscope (AFM) cantilevers with different stiffnesses and tips. From the experiments, frictional behaviors and friction maps according to load/pressure and materials were obtained on the various semiconductor material surfaces. Contact stiffnesses were observed in various tip-surface contact situations. Based on the experimental results, the relationship between the frictional behaviors observed, contact stiffness, and particle-surface material was carefully investigated.
입자 연마 가공에서의 연마 입자-공작물 표면간 접촉에 따른 마찰해석
성인하(In-Ha Sung),한흥구(Hung-Gu Han),공호성(Hosung Kong) 한국트라이볼로지학회 2009 한국트라이볼로지학회 학술대회 Vol.2009 No.11
In this paper, the relationship between the material removal rate and the interfacial mechanical properties at particle-surface contact situation, which can be seen in an abrasive machining process using micro/nano-sized particles, was discussed. Friction and stiffnesses were measured experimentally on an atomic force microscope (AFM) by using colloidal probes which have a silica colloid particle in place of tip to simulate a particle-flat surface contact in an abrasive machining process. From the experimental investigation and theoretical contact analysis, the interfacial contact properties such as lateral stiffness of contact, friction, the material removal rate were presented with respect to some of material surfaces and the relationship between the properties as well.
UV-Vis 분광분석에 의한 전기변압기 내 절연지 열화도 측정
공호성(Hosung Kong),한흥구(Hung-Gu Han) 한국트라이볼로지학회 2019 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.35 No.3
Insulated oil degradation produces charged by-products, such as acids and hydro-peroxides, which tend to reduce the insulating properties of the oil. In this study, UV-vis spectroscopy measurement technology is developed and experimentally compared with other measurement methods, such as the titration method and IR spectroscopy, to validate its ability to monitor the degradation of electrical insulating paper. The degradation characteristics of the insulating paper are appropriately represented through various types of measurement methods, such as the Tan (delta) method, CO₂ gas production measurement, the titration method, and IR spectroscopy. The results are demonstrated to be well comparable to a change in the fluorescence emission ratio (FER), which is defined as the shift in fluorescence intensity in the measured wavelength range, and also to the chromatic ratio, which is defined as a color shift to longer wavelength ranges. The results also show that, by using UV-vis spectroscopy, it is possible to detect the degradation of the insulating paper. This study suggests that UV-vis spectroscopy can be applied as an alternative to high-performance liquid chromatography, which is the internationally recognized measurement technology for cellulose paper degradation. The FER detector is also verified to be useful as an effective condition-monitoring device for power transformers.
공호성(Hosung Kong),한흥구(Hung-Gu Han),김진욱(Jin Uk Kim),김경석(Kyoung Seok Kim),박종식(Jong Sik Park) 한국트라이볼로지학회 2019 한국윤활학회지(윤활학회지) Vol.35 No.2
This work aims to develop a dry lubricant for oilless bush, especially a solid lubricant, thereby creating a coating method with improved properties of anti-friction and load-carrying capacity without oil lubrication. In this work, spherical-shaped powders of thermosetting resin such as polyimide (PI) are mixed with a binder matrix obtained by mixing a fluorocarbon compound resin such as Polytetrafluoroethylene (PTFE) or Ethylene tetra fluoro ethylene (ETFE) with itself or with a non-fluorocarbon thermoplastic resin such as Polyether ether ketone (PEEK). And these dry lubricant mixtures are thickly coated (200-300 mm in the thickness) on the inner surface of the bush by using a wet-typed air-spray deposition method. It was found that the load-carrying capacity of the solid lubricant for excavator bush (60 mm in diameter) that operates under a high load condition (at 40 MPa) is greatly improved owing to the spherical-shaped powders of thermosetting resin. In addition, the coefficient of friction at the sliding surface is also reduced less than 0.1. Thick coating also lowers the contact stress at the edge of a bush that results in better tribological performances. The result suggests that the lubrication performance and durability life of the bush can be remarkably improved even without lubrication (oil or grease).
성인하(In-Ha Sung),한흥구(Hung-gu Han),공호성(Hosung Kong) 한국트라이볼로지학회 2009 한국윤활학회지(윤활학회지) Vol.25 No.2
Interests in micro/nano-particles have been greatly increasing due to their wide applications in various fields such as environmental and medical sciences as well as engineering. In order to obtain a fundamental understanding of the tribological characteristics at particle-surface contact interface, frictional behaviors according to load/pressure and materials were obtained by using atomic force microscope (AFM) cantilevers with different stiffnesses and tips. Lateral contact stiffnesses were observed in various tip-surface contact situations. Experimental results show that stick-slip friction behavior occurs even when the colloidal probes with a particle of a few micrometers in diameter, which have a relatively large contact area and lack a well-shaped apex, were used. This indicates that atomic stick-slip friction may be a more common phenomenon than it is currently thought to be. Also, experimental results were investigated by considering the competition between the stiffness of the interatomic potential across the interface and the elastic stiffnesses of the contacting materials and the force sensor itself.