• 제목/요약/키워드: Wear mechanisms

검색결과 161건 처리시간 0.02초

인청동의 내마모성향상에 대한 연구 (A Study on the Improvement of the Wear Resistance of P-bronze)

  • 송건;권숙인;차영현
    • Tribology and Lubricants
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    • 제4권1호
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    • pp.56-68
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    • 1988
  • The wear resistance of P-bronze which is widely used as worm gear material was investigated. In order 1o study the effect of additional elements on the wear resistance of Pbronze, the applied load and sliding time were selected as variables, and SCM4, were used as against metal. The addition of Fe improve wear resistance, for it precipities hard Fe$_3$ P phase and the work hardening coefficients are lowered due to decreasing solubility of P. When Fe is added in conventional P-bronze, the alloy is rather sliding than forming wear debris by frictional force during wear test. Experimental results indicated that the wear mechanisms for P-bronze are mainly consisted of abrasive wear due to Beilby layer forming mechanism and adhesive wear due to thermally activated wear mechanism. Moreover, the weight loss is decreased in accordance with increasing load and time. However the rate of wear loss is decreased as the sliding time is increased.

유리섬유강화 복합재료의 미끄럼 속도변화에 따른 마모 특성 (Characteristics of Wear on Sliding Speed of Glass Fiber Reinforcement Composites)

  • 김형진;고성위
    • 수산해양기술연구
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    • 제48권3호
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    • pp.277-283
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    • 2012
  • The characteristics of abrasive wear on sliding speed of glass fiber reinforcement (GF/PUR) composites were investigated at ambient temperature by pin-on-disc friction test. The cumulative wear volume, friction coefficient and surface roughness of these materials on sliding speed were determined experimentally. The major failure mechanisms were lapping layers, deformation of resin, ploughing, delamination, and cracking by scanning electric microscopy (SEM) photograph of the tested surface. As increasing the sliding speed the GF/PUR composites indicated higher friction coefficient. The surface roughness of the GF/PUR composites was increased as the sliding speed was higher in wear test.

플라스틱재료의 왕복동마찰마멸거동 (Reciprocating sliding wear behavior of plastics against steel)

  • 김충현;안효석;정태형
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1999년도 제30회 추계학술대회
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    • pp.35-41
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    • 1999
  • Friction and wear test was performed for nylon, acetal resin, and PTFE(polytetrafluoroethylene) under reciprocating dry sliding conditions against a steel counterpart. Friction coefficient and specific wear rate were analysed as a function of sliding distance and applied load. The worn surfaces of plate and disc specimens were observed using SEM(Scanning Electron Microscopy). The experimental results show that acetal resin exhibited lowest wear rates whereas PTFE possessed lowest friction coefficient. The prominent wear mechanisms found were adhesion and abrasion.

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Microstructural Wear Mechanism of $Al_2O_3-5$ vol% SiC nanocomposite and $Si_3N_4$Ceramics

  • Riu, Doh-Hyung;Kim, Yoon-Ho;Lee, Soo-Wohn;Koichi Niihara
    • 한국분말재료학회지
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    • 제8권3호
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    • pp.179-185
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    • 2001
  • Through the observation of wear scar of two ceramic materials, microstructural wear mechanisms was investigated. As for the $Al_2O_3$-5 vol% SiC nanocomposite, the grain boundary fracture was suppressed by the presence of SiC nano-particles. The intragranular SiC particles have inhibited the extension of plastic deformation through the whole grain. Part of plastic deformation was accommodated around SiC particles, which made a cavity at the interface between SiC and matrix alumina. On the other hand, gas-pressure sintered silicon nitride showed extensive grain boundary fracture due to the thermal fatigue. The lamination of wear scar was initiated by the dissolution of grain boundary phase. These two extreme cases showed the importance of microstructures in wear behavior.

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플라즈마사용법에 의한 $ZrO_2-Y_2O_3$ 코팅의 고온에서의 마모 (High Temperature Wear of Plasma-Sprayed $ZrO_2-Y_2O_3$ Coatings)

  • 김장엽;임대순;안효석
    • 한국세라믹학회지
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    • 제30권12호
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    • pp.1059-1065
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    • 1993
  • The sliding wear behavior of the plasma sprayed zirconia containing 8wt% yttria was investigated over a range of room temperature to 800℃. Both of the friction coefficient and the wear loss increased reaching its maximum at about to 499℃. and then decreased again with increasing temperature up to 800℃. The worn surface at elevated temperature were observed and analyzed by scanning electron microscopy and X-ray diffractometer to study the mechanisms of high temperature wear behavior. Surface morphology of the worn samples changes with temperature. Monoclinic (m)/tetragonal (t) x-ray peak intensity ratio of wear debris and worn surface decreased with increasing temperature. Non-transformable tetragonal (t') to metastable tetragonal (t) phase transformation of worn surface increased with increasing temperature. The results indicate that dehumidification and above phase changes are contributing to the high temperature wear behavior of the plasma sprayed ZrO2-Y2O3 coatings.

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선접촉시 세라믹의 마찰 및 마멸 특성에 미치는 속도와 하중의 영향 (The Effects of Sliding Speed and Load on Tribological Behavior of Ceramics in Line-contact Sliding)

  • 김영호;이영제
    • Tribology and Lubricants
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    • 제11권4호
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    • pp.35-44
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    • 1995
  • Within the practical ranges of speed and load, the formation of transfer films and the consequent effects on the friction and wear behavior of ceramic materials during repeated pass sliding contact were studied. These tests were done using $Al_{2}O_{3}$, SiC and $Si_{3}N_{4}$ with the cylinder-on-flat test configuration. The three pairings behaved differently, even if some wear mechanisms were common to the three systems. The $Al_{2}O_{3}$ pair showed the least wear in overall conditions, followed by the $Si_{3}N_{4}$ pair in harder sliding conditions. The wear of SiC was very high at severe loading. In case of $AL_{2}O_{3}$ and $Si_{3}N_{4}$, the transfer film, whenever formed, is strongly attached, enough to resist being wiped off by the slider. As a consequence, the formation of this f'fim leads to a decrease in the wear rate because of the protecting role of the film. The presence of the film at the contact interface also results in high friction. Also, the wear rate of each ceramics is related to the frictional power provided by load, speed and friction.

FRP 선박 외판재의 연삭마모 특성에 관한 상대재 거칠기의 영향 (Effect of Counterpart Roughness on Abrasive Wear Characteristics of Side Plate of FRP Ship)

  • 김형진;고성위;김재동
    • 한국해양공학회지
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    • 제22권6호
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    • pp.35-40
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    • 2008
  • The effect of counterpart roughness on abrasive wear characteristics of side plate materials of FRP ship, which were composed of glass fiber and unsaturated polyester resin composites, were investigated at ambient temperature by pin-an-disc friction test. The friction coefficient, wear rate and cumulative wear volume of these materials against SiC abrasive paper were determined experimentally. The wear rate of these materials decreased rapidly with sliding distance and then maintained a constant value. It was increased as counterpart roughness was rougher in a wear test. The cumulative wear volume tended to increase nonlinearly with sliding distance and depended on applied load and sliding speed for these composites. It could be verified by SEM photograph of fracture surface that major failure mechanisms were overlapping layers, microcutting, deformation of resin, delamination, and cracking.

STD 11강 마모특성에 미치는 서브제로처리의 영향 (Effect of Cryogenic Treatment on Wear Resistance of STD 11 Steel)

  • 홍영환;송건
    • 열처리공학회지
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    • 제16권3호
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    • pp.134-140
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    • 2003
  • Effects of cryogenic treatment and tempering temperature on the amount of retained austenite, hardness and wear properties has been investigated using alloy tool steel, STD 11. Cryogenic treatments were performed at the temperatures of $-100^{\circ}C$, $-150^{\circ}C$ and $-196^{\circ}C$, and tempering were performed at $200^{\circ}C$ and $530^{\circ}C$. It was shown that lower hardness value was obtained on high temperature ($530^{\circ}C$) tempering even after cryogenic treatment. And retained austenite was not entirely transformed to martensite after cryogenic treatment even at $-196^{\circ}C$, which was not consistent with the belief that $-80^{\circ}C$ was sufficient to entirely transform any austenite retained in the quenched microstructure. Austenite retained in cryogenic treated condition was completely transformed to martensite only after tempering at $530^{\circ}C$. As far as wear test conditions in this investigation, it was found that cryogenic treatments improved the sliding wear resistance, but improvement of wear resistance was not directly related with retained austenite contents. And it was found that predominent wear mechanisms of STD 11 steel were oxidation wear and adhesive wear In sliding wear conditions.

부품 및 벤치 실험을 통한 폴리우레탄 유압 왕복 실의 가속 실험 (Component and Bench Tests of Polyurethane Hydraulic Reciprocating Seal for Accelerated Life Testing)

  • 제영완;김한솔;김류운;정구현;안중혁;전홍규
    • Tribology and Lubricants
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    • 제30권5호
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    • pp.271-277
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    • 2014
  • Hydraulic reciprocating seals have been widely used to prevent fluid leakage and to provide lubricant film on counter surface in various hydraulic system. The degradation of the seal may cause the catastrophic failure of the hydraulic system. To assess the durability of the seals and the compatibility with counter surface, accelerated life testing (ALT) has been typically employed from industry. However, ALT often takes up to a few months to cause a failure of the seals, and therefore, there is a need to develop more efficient ALT methods. In this work, the degradation characteristics of polyurethane (PU) seals from field test are investigated and they are compared to those from the component and bench tests, with an aim to contribute to the development of ALT method. From the comparison of the cross-sectional profiles of the sealing surface of the PU specimens before and after the tests, both wear and compression set are found to be responsible for degradation of the PU seals. It is also shown that the major wear mechanisms of the PU seals from the field is abrasive wear and formation of pits. The component and bench tests performed in this work are shown to reproduce such wear mechanisms, and therefore, those test methods can be used as an ALT method for PU seals. In particular, the bench test proposed in this work may be effectively utilized to assess the durability and the compatibility of the seals with the counter surface. The results of this work are expected to aid in the design of ALT for PU seal.

Effect of an temperatures of post-spray heat treatment on wear behavior of $8%Y_2O_3-ZrO_2$ coating

  • Chae, Y.H.;Kim, S.S.
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.181-182
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    • 2002
  • Most recent, Plasma ceramic spray is used on parts of tribosystem, has been investigated on the tribological performance. The application of ceramic coatings by plasma spray has become essential in tribosystems to produce better wear resistance and longer life in various conditions. The purpose of this work was to investigate the wear behavior of $8%Y_2O_3-ZrO_2$ coating due to temperatures of post-spay heat treatment. The plasma-sprayed $8%Y_2O_3--Zirconia$ coating was idiscussed to know the relationship between phase transformations and temperatures of post- spray heat treatment. Wear tests was carried out with ball on disk type on normal load of 50N, 70N and 90N under room temperature. The transformation of phase and the value of residual stress were measured by X-ray diffraction method(XRD). Tribological characteristics and wear mechanisms of coatings was observed by SEM. The tribologieal wear performance was discussed a point of view for residual stress. Consequently. post-spray heat treatment plays an important role in decreasing residual stress. Residual stress in coating system has a significant influence on the wear mechanism of coating.

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