• Title/Summary/Keyword: Friction/Wear

Search Result 1,231, Processing Time 0.031 seconds

Wear characteristics on particle volume fraction of nano silica composite materials (입자 함유율의 변화에 따른 나노 실리카 복합재료의 마모 특성)

  • Lee, Jung-Kyu;Koh, Sung Wi
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.49 no.4
    • /
    • pp.492-499
    • /
    • 2013
  • The characteristics of abrasive wear of the rubber matrix composites filled with nano sized silica particles were investigated at ambient temperature by pin-on-disc friction test. The range of volume fraction of silica particles tested are between 11% to 25%. The cumulative wear volume and friction coefficient of these materials on particle volume fraction were determined experimentally. The major failure mechanisms were lapping layers, deformation of matrix, ploughing, deboding of particles and microcracking by scanning electric microscopy photograph of the tested surface. The cumulative wear volume showed a tendency to increase nonlinear with increase of sliding distance. As increasing the silica particles of these composites indicated higher friction coefficient.

Comparison with Properties of Friction and Wear for Cam/Tappet Material (CAM/TAPPET 재료조합에 따른 마찰${\cdot}$마모특성 비교)

  • Song Keun-Chul;Kim Kyung-Woon
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2003.11a
    • /
    • pp.105-111
    • /
    • 2003
  • The valve train system of engines has long been a sensitive area with respect to wear performance because of the high contact loads and surface sliding speeds encountered. In particular, wear problems of load-carrying components in relative motion, such as cam and tappet in valve train system have made troubles. To overcome these problems, combination of proper materials is important, as well as selecting of high wear performance materials. This paper presents the experimental result of friction and wear properties of ca/tappet materials. To investigate friction and wear properties for several combinations of materials, using commonplace tribometer(Plint 77, reciprocating type), we make a selection of a optimum material combination.

  • PDF

Characteristics of Friction and Wear of Polymer/MoS$_2$ Composites (고분자/$MoS_2$ 복합재료의 마찰 및 마모특성)

  • 문탁진;윤호규
    • Tribology and Lubricants
    • /
    • v.5 no.1
    • /
    • pp.12-20
    • /
    • 1989
  • The friction and wear behavior of molybdenum disulfide filled polymer composites sliding against metal has been investigated using pin-on-disc machine and microscope. The observed wear rates were reduced by the addition of MoS$_2$ to nylon and this can be attributed to the homogenous transfer of MoS$_2$ to the counteddace thereby modifying sliding conditions. The friction of filled and unfilled nylon was increased with increasing sliding speed, and the catastropic wear rate was occurred at high normal load. This have been explained by thermal degradation. In the case of HDPE, however, the wear rate was not always reduced by the addition of MoS$_2$ and the influence of MoS$_2$ was mainly even the opposite. Filled and unfilled HDPE had lower values of friction and wear rate than those of nylon. Micrographs appeared that the delamination of the worn surface in nylon/MoS$_2$ composite occurred and revealed that the worn surface of HDPE presented a number of characteristic features as wear grooves, pulls, and smears and crescents.

Friction and Wear Behaviors of WC-Co/WC-Co Pairs in Air

  • Hosokawa, H.;Nakajima, T.;Shimojima, K.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
    • /
    • 2006.09a
    • /
    • pp.629-630
    • /
    • 2006
  • To investigate sliding friction and wear behaviors of WC-Co/WC-Co pairs containing different WC grain sizes, the ball-on-disc test in air were carried out, where WC grain sizes a $0.5\;{\mu}m$ (F.G.) and $1.5\;{\mu}m$ (C.G.). The wear volume of F.G. pin for F.G. pin/C.G. disc is larger than that of F.G. pin for F.G. pin/F.G. disc due to higher friction coefficient, and the surfaces after wear test are richer in oxygen compared to those before test. Furthermore, the wear debris, which is composed of nona-scale grain, after the wear test are remarkably richer in oxygen than to those before test.

  • PDF

Reciprocating sliding wear of nylon and polyacetal against steel (나일론과 폴리아세탈의 마찰마멸특성에 관한 고찰)

  • 김충현;안효석;정태형
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 1999.06a
    • /
    • pp.203-208
    • /
    • 1999
  • Friction and wear test have been performed on nylon, polyacetal, and PTFE(polytetrafluoroethylene), in reciprocating dry sliding conditions against a steel disc. According to the results, polyacetal show lowest wear rates and PTFE was found to exhibit lowest friction coefficient. The prominent wear mechanism found were adhesion and abrasion.

  • PDF

Evaluation of wear chracteristics for $Al_{2}O_{3}-40%TiO_{2}$ sprayed on casting aluminum alloy (주조용 알루미늄합금의 $Al_{2}O_{3}-40%TiO_{2}$ 용사층에 대한 마멸특성 평가)

  • 채영훈;김석삼
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 1997.10a
    • /
    • pp.183-190
    • /
    • 1997
  • The wear behaviors of $Al_2O_3-40%TiO_2$ deposited on casting aluminum alloy(ASTM A356) by plasma spray against SiC ball have been investigated experimentally. Friction and wear tests are carried out at room temperature. The friction coefficient of $Al_2O_3-40%TiO_2$ coating is lower than that of pure $Al_2O_3$ coating(APS). It is found that low friction correspond to low wear and high friction to high wear in the experimental result. The thickness of $Al_2O_3-40%TiO_2$ coatings indicated the existence of the optimal coating thickness. It is found that a voids and porosities of coating surface result in the crack generated. As the tensile stresses in coating increased with the increased friction coefficient. The columnar grain of coating will be fractured to achieve the critical stress. It is found that the cohesive of splats and the porosity of surface play a role in wear characteristics. It is suggested that the mismatch of thermal expansion of substrate and coating play an important role in wear performance. Tensile and compressire under thermo-mechanical stress may be occurred by the mismatch between thermal expansion of substrate and coating. This crack propagation above interface is observed in SEM.

  • PDF

Tribological characteristics of short fiber reinforced composites (단섬유 보강 복합재료의 트라이볼로지 특성)

  • 윤재륜
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.12 no.6
    • /
    • pp.1238-1245
    • /
    • 1988
  • Friction and wear characteristics of short fiber reinforced and particulate filled composites were investigated experimentally. Two kinds of fiber composites, chopped graphite fiber reinforced PAI(polyamide-imide) and glass fiber reinforced PAI, and a particulate composite, TiO$_{2}$ powder filled PAI, were selected for the friction and wear test since these are important engineering materials based on a new high temperature engineering plastic. All the specimens were cut into proper size for cylinder-on-plate type wear test. Frictional forces were measured by employing a load transducer and wear rates were calculated by measuring weight loss during wear test. The experimental results are reported in this paper and carefully discussed to explain the friction and wear behavior qualitatively. The frictional behavior is interpreted by considering four basic friction components which are believed to the genesis of friction and the wear behavior is explained by applying delamination theory of wear.

Investigation of the Effect of Wear Particles on the Acoustic Emission Signal (마모 입자가 음향방출신호에 미치는 영향에 관한 연구)

  • Han, Jae-Ho;Shin, Dong-Gap;Kim, Dae-Eun
    • Tribology and Lubricants
    • /
    • v.35 no.5
    • /
    • pp.317-322
    • /
    • 2019
  • In spite of progress in tribological research, machine component failure due to friction and wear has been reported frequently. This failure may lead to secondary damage that can cause huge expense for maintenance and repair. To prevent economic loss, it is important to detect and predict the initial failure point. In this sense, various researchers have been tried to develop Condition Monitoring (CM) method using Acoustic Emission (AE) generated while the materials undergo failure. In this study, effect of particles on friction and wear was investigated using the pin-on-plate friction test and AE signal was recorded with a band-width type AE sensor. The experiments were performed in dry and lubricant conditions using steel and glass as specimens. After the experiment, 3D laser microscope image was captured to evaluate the wear behavior quantitatively. The AE signal was analyzed in time-domain and frequency-domain. The amplitude was compared with the frictional results. The results of this study showed that particle generation accelerate wear, generate high magnitude AE signal and change the frequency characteristics of the signal. Also, lubricant condition test results showed low coefficient of friction, low wear rate, and low magnitude of AE signal compared to the dry condition. It is expected that the results of this study will aid in better assessment of wear in CM technology

A study on the cutting characteristics of SUS304 by flank wear (Flank 마모에 의한 SUS304의 절삭특성에 관한 연구)

  • Yu, Ki-Hyun;Cheong, Chin-Yong;Seo, Nam-Seob
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.11 no.2
    • /
    • pp.182-188
    • /
    • 1994
  • This expermintal study is intended to investigate he development of flank wear in turning os SUS304 which is used in industrial applications and is acknowledged as a machining difficult material. In cutting process, change of velocity, change of feed, and change of depth of cut were investigated about the effect of flank wear, and slenderness ratio is also investigated. The variations of unit cutting force with the change of rake angle and the change of uncut chip area are observed. The friction angles are calculated for the change friction force and observed. The friction angles are calculated for the change friction force and normal forcd on the different rake angles. From this experimental study, the following results can be said. 1. Under the high cutting speed condition, the flaank wear is affected by the feed and depth of cut, but the influence of feed and depth of cut to the flank wear is reduced when the velocity is low. 2. The smaller slenderness ratio is, the shorter the tool life results in high cutting speed, and the lower cutting speed is, the lower the effect of slenderness ratio to the flank wear is. 3. Using the characteristics of force-RMS, the flank wear of a tool can be detected. There are almost no differences between the RMS characteristics of cutting force and feed force.

  • PDF

Fundamental Behavior Analysis of SCM440 Steel on Friction and Wear (SCM440강에 대한 마찰 마멸의 기본적 거동해석)

  • Byun, Jae-Young;Lee, Chang-Ju;Jang, Jun-Soo;Choi, Won-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.15 no.1
    • /
    • pp.74-80
    • /
    • 2016
  • Due to the increased use of power caused by industrial development, the importance of improving wear and friction in the contact region has emerged. Except for some parts, such as brakes or clutches and friction, seals and precision mechanical parts (e.g., pistons, bearings, valves, and cams) are important engine components that require low friction characteristics. In this study, the experimental method used to determine the friction characteristics was based on the type of rpm with the pin-on-disc test device, the element analysis program ANSYS was used to analyze the surfaces of the two metals rubbing together, and physical formation FEM models were used to study the properties and wear. The friction coefficient of variation was unsafe, but at the start of wear, it converged to a stable friction coefficient that increased after a certain slip away.