• Title/Summary/Keyword: Wear Coefficient

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Tribological Characteristics for High Perfomance Metallic Friction Materials (고성능 금속마찰재의 트라이볼로지적 특성)

  • 김석삼;김재호;안효준
    • Tribology and Lubricants
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    • v.14 no.1
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    • pp.45-53
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    • 1998
  • Friction and wear test for two kinds of Cu-based sintered metallic friction material against cast iron disk was carried out by plate-on-disk type friction and wear tester to investigate the friction and wear characteristics of brake system in severe condition. In this experimental study, the counter specimen was cast iron which is being used generally in brakes of heavy duty equipments. Test friction materials were A type which was manufactured by foreign company and B type by domestic company. Friction coefficient and wear volume were measured and compared with each other. The experiment was performed under room temperature. The worn surface of cast iron disk and friction material were observed by scanning electron microscope. The temperature of surface of disk was measured continuously by the non-contacting thermometer. It was found that A type friction material had stable friction coefficient over the wide range of sliding condition, but B type friction material had unstable friction coefficient and lower value of 0.2 under the severe sliding condition.

A Study on the Friction and Wear Property of Composite Piston Ring for Oil Free Air Compressor (무급유 공기압축기용 복합재료 피스턴링의 마찰마모 특성에 관한 연구)

  • Kim, Y.Z.;Jung, H.D.;Kim, Y.H.
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.766-771
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    • 2000
  • This study is mainly concerned with friction and wear properties for the piston ring of non-lubricating air compressor which made of PTFE-polyimide composites. At the PTFE and polyimide alone mixture specimens, PTFE80%-polyimide20%, which shows the lowest men friction coefficient and specific wear rate at 0.94m/s sliding speed. At each of carbon, copper and oxide lopper mixed with PTFE80%-polyimide20%. In case of copper10%, at 0.94m/s sliding speed, the mean friction coefficient shows 0.087, which is the lowest value in all specimens. In case of the specific wear rate, copper30% specimen shows the lowest value of $2.537E-5(mm^3/Nm)$ in all specimens.

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Friction Coefficient and Microstructure of Reaction-Bonded Silicon Carbide According to Sliding Conditons (반응소결 탄화규소의 접동조건에 따른 마찰계수 및 미세구조)

  • 김호균;김인섭;이병하
    • Journal of the Korean Ceramic Society
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    • v.32 no.7
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    • pp.825-831
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    • 1995
  • Reaction-bonded SiC-Si material was fabricated by infiltration of Si melt into a mixture of $\alpha$-SiC and carbon at 175$0^{\circ}C$ under the vacuum atmosphere. Wear properties were analyzed by ball-on-plate wear tester, changing loading weight, sliding speed, sliding time and atmosphere, Results showed that the friction coefficient was decreased with increasing load and sliding velocity. The lowest friction coefficient of 0.05 was obtained under an oil atmosphere. The analysis of the wear surface indicated that the areas wehre particles were pulled out and where free silicon particles worn out preferentially serve as liquid reservoirs to decrease the wear resistance.

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Tribological Characteristics of Carbon Fiber Reinforced Plastics by Surface modification (탄소섬유복합재의 표면개질에 따른 트라이볼로지 특성에 관한 연구)

  • 전승흥;양준호;오성모;이봉구
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.11a
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    • pp.29-36
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    • 2000
  • This investigation has been studied about friction and wear properties which were important problem, when carbon fiber reinforced plastic(CFRP) was used practically. Unidirection carbon fiber reinforced composites was fabricated with epoxy resin matrix and carbon fiber as a reinforced, and its surface was modified by the ion-assisted reaction. And then we tested the their friction and wear properties according to the ion-irradiation. when the amount of ion-irradiation was 1${\times}$10l6$\^$16/ ions/$\textrm{cm}^2$, the friction coefficient values were about 0.1, where as, the friction coefficient values of non-treatment composites were about 0.16. The former was the stablest in wear mode. We know that ion-irradiation was not proportioned to the friction coefficient, so we found the optimal conditions of the friction and wear according to the ion-irradiation.

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The effect of solid lubricant on the frictional characteristics of Cu base sintered friction material. (소결 마찰재의 마찰특성에 미치는 고체 윤활제의 영향)

  • 정진현;이범주;조정환;정동윤;권석진
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1996.04b
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    • pp.45-54
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    • 1996
  • The effect of graphite on the frictional characteristics of Cu-based sintered friction materials was studied by pin-on-disk type wear test. A study has been carried out concerning the optimum concentration of graphite in sintered friction material to obtain the minimum wear rate and low friction coefficient . Friction coefficient and wear rate were increased as increasing the content of graphite in the matrix. In the study the optimum concentration of graphite was 19vol % to get the minimum wear rate and optimal frick'ion coefficient.

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The Sliding Wear Behavior of Inconel 600 Mated with SUS 304 (SUS 304에 대한 Inconel 600의 Sliding 마모거동)

  • Kim, Hun;Choi, Jong-Hyun;Kim, Jun-Ki;Park, Ki-Sung;Kim, Seung-Tae;Kim, Seon-Jin
    • Korean Journal of Materials Research
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    • v.11 no.10
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    • pp.841-845
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    • 2001
  • The steam generator tubes of power plant damaged by sliding wear due to flow-induced motion of foreign object. Amount of wear have been predicted by Achard's wear equation until now. However, there are large error and low reliability, because this equation regards wear coefficient(k) as constant. The sliding wears tests have been performed at room temperature to examine parameters of wear (wear distance, contact stress). The steam generator tube material for wear test is used Inconel 600 and foreign object material is used 304 austenite stainless steel. The sliding wear tests show that the amount of wear is not linearly proportional to the wear distance(for 374 austenite stainless steel). According to experimental result, wear coefficient is not constant k but function k(s) of wear distance. The newly modified wear predictive equation V=k(s)F have small error and high reliability.

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마멸입자가 운동이력이 다른 금속재료의 마찰 마멸현상에 미치는 영향

  • 황동환;김대은;이상조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.807-810
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    • 1995
  • The effects of weae particles on the friiction and wear behavior of metals in dry sliding conditions are presented. The tribological test were performed using pure metal specimens which were selected based on their degrees of compatibility and hardness ratio. Friction and wear experiments were conducted using both pin-on-disk and reciprocating pin-on-plate type tribotesters to investigate the effect of motion history. Experimental results show that in the case of dry sliding the frictional behavior observed during pin-on-disk test differed form that of pin-on-reciprocator test for the given set of material pairs. The friction coefficient and wear rate were found to be higher for the pin-on-disk tests. It is suspected that the sliding motion of the pin affects the wear particle dynamics, which in turn influences the frictional behavior. The effect of material pair properties seemed to be relatively smaller than that of wear particles. The results of this paper is expected to aid in the design of mechanical systems for best tribological performance.

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Oxidation and Fretting Wear Characteristics of Zirconium Alloy Tubes (지르코늄 합금 튜브의 산화와 프레팅 마멸 특성)

  • Chung, Il-Sup;Lee, Ho-Seong;Lee, Myung-Ho
    • Tribology and Lubricants
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    • v.25 no.4
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    • pp.250-255
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    • 2009
  • Oxidation characteristics of Zirlo and Zircaloy-4 tubes, which are widely used as nuclear power fuel cladding, are studied in steam environment up to $1200^{\circ}C$. Oxidation resistances are compared in terms of the mass increase due to the absorption of oxygen. The evolution of microscopic structure accompanied with the oxidation process is investigated. Also, the influence of oxidation on the fretting wear characteristics of the tubes is studied. Piezo-electrically actuated rig is employed to fret the tubes with cross-contacting arrangement. Wear scar is observed and measured, by using microscopes and a 3D-profiler. The results of fretting wear are quantified in terms of scar size, wear volume and wear coefficient, and compared for the three different tube materials of oxidated Zirlo, virgin Zirlo and Zircaloy-4.

The research on wear simulation between wheel and rail at inclined of Korea High Speed Railway (경사선로에서의 차륜과 레일간 상호작용에 따른 마모 현상 연구)

  • Moon Tai-Seon;Seo Bo-Pil;Choi Jeung-Hum;Han Dong-Chul
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2003.11a
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    • pp.112-117
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    • 2003
  • The purpose of this work is to general approach to numerically simulating wear in rolling and sliding contact area between wheel and rail interface based on the analysis of dynamics with general MBS package. A simulation scheme is developed that calculates the wear at a detailed level. The estimation of material removal follows Archard's wear equation which states that the reduction of volume is linearly proportional to the sliding distance, the normal applied load and the wear coefficient and inverse proportional to hardness. The main research application is the wheel-rail contact of Korea High Speed Railway.

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Effect of load upon the abrasive wear characteristics of glass fiber reinforced polyurethane composites (하중변화에 따른 GF/PUR 복합재료의 연삭마모특성)

  • Koh, Sung-Wi
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.4
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    • pp.495-502
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    • 2010
  • The effect of load and sliding speed on abrasive wear characteristics of glass fiber/polyurethane (GF/PUR) composites were investigated at ambient temperature by pin-on-disc friction test. The friction coefficient, cumulative wear volume and surface roughness of these materials against SiC abrasive paper were determined experimentally. Experimental results showed that the surface roughness of the GF/PUR composites was increased as applied load was higher in wear test. The cumulative wear volume tended to increase nonlinearly with increase of sliding distance and depended on applied load and sliding speed for these composites. It could be verified by scanning electric microscopy (SEM) photograph of surface tested that major failure mechanisms were lapping layers, ploughing, delamination, deformation of resin and cracking.