• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.141-144
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• 2006

In this study, the friction and wear characteristics of pure epoxy and silica-filled epoxy resin composites with average silica particle diameter of $6-33{\mu}m$ were investigated at ambient temperature by pin-on-disc friction test. The cumulative wear volume, friction coefficient and wear rate of these materials against SiC abrasive paper were determined experimentally. The cumulative wear volume tended to increase nonlinearly with increase of sliding distance and depended on diameter of the silica particle for all these composites. The sliding wear tests of the materials demonstrated that the friction coefficient and the wear rate of silica filled epoxy composites were lower than those of the pure epoxy. silica filled epoxy.

• Journal of Ocean Engineering and Technology
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• v.22 no.6
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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.

• Journal of Welding and Joining
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• v.14 no.3
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• pp.66-74
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• 1996

In this study, friction and wear properties of flame sprayed specimens and hard Cr plating specimens were tested, and their properties were compared each other in dry and lubrication condition. Ni-Cr powder and steel powder were used as the spray powder and sprayed on the steel(S45C) substrate by flame sprayed method. Each wear surface was observed with SEM after friction and wear test. The friction coefficient of the as-forged steel specimens was the highest among surface treatment specimens, and the other specimens appeared in order as follows ; hard Cr-plating specimens, Ni-Cr powder sprayed specimens, steel powder sprayed specimens. Comparing the wear volumes in dry condition, as forged steel specimens appeared the greatest wear volume, and the other specimens appeared wear volume in order as follows ; Ni-Cr powder sprayed specimens, steel powder sprayed specimens, hard Cr plating specimens. In friction and wear test, the hard Cr plating specimens were worn by the abrasive phenomenon, involving the cracks. The wear volume of steel powder sprayed specimens was lower than that of Ni-Cr powder sprayed specimens. Comparing the tensile strength of both sprayed coating layers, the steel powder sprayed coating layer was better than Ni-Cr powder sprayed coating layer.

• Tribology and Lubricants
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• v.33 no.3
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• pp.98-105
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• 2017

A pin-on-disk test is performed to measure the wear volume of a ductile cast iron (DCI) roll when it wears down using a high carbon steel and two alloy steels at different sliding velocities between the roll and the material (steel). Normal pressure is set as constant and test temperatures are 400, 500 and $600^{\circ}C$. In addition, thermal softening behavior of the DCI roll is examined using a high-temperature micro-hardness tester and the surface hardness variation of the DCI roll is expressed in terms of temperature and heating time. Based on experimental data, a wear coefficient used in Archard's wear model for each material is obtained. The wear volume is clearly observed when the test temperature is $400^{\circ}C$ and sliding velocity varies. However, it is not measured at temperatures of $500^{\circ}C$ and $600^{\circ}C$ even with variations in sliding velocity. From the optical photographs of the pin and disk, the abrasive wear is observed at $400^{\circ}C$ clearly, but no at $500^{\circ}C$ and $600^{\circ}C$. At higher temperatures, the pin surface is not smooth and has many tiny caves distributed on it. It is found that wear volume is dependent on the carbon contents rather than alloy contents. Results also reveal that the variations of wear coefficients are almost linearly proportional to the carbon contents of the material.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.6
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• pp.547-555
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• 2016

The wheel wear of a railway vehicle is mainly generated when maneuvering on a curved track. The change in the wheel profile affects the dynamic stability of the vehicle. In this analysis, the wheel wear volume was calculated while changing the velocity and radius of the curve to analyze the wear characteristics of a wheel at a curved section. The wear index was calculated from a vehicle dynamic analysis based on a multibody dynamics analysis and wear volume from a wear model by British Rail Research. The wear volume at a radius of 300 m is dominant compared with other radii. The wear volume was calculated by assigning different coefficients of friction to the tread and flange of the wheel to investigate the effect of lubrication on the wear characteristics. The effect of the improvement by lubrication is calculated by varying the radius of the track, and is assessed on an actual urban railway section.

• Tribology and Lubricants
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• v.14 no.4
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• pp.88-94
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• 1998

The fretting wear characteristics of Zircaloy-4 tube in light water were investigated experimentally. A fretting wear tester was designed to be suitable for this fretting test. This study was focused on the effects due to the combination of normal load, slip amplitude and number of cycles as the main factors of fretting. The results of this study showed that the wear volume increased abruptly at slip amplitude above 100 ${\mu}{\textrm}{m}$, which is defined as critical slip amplitude of Zircaloy-4 tube in light water, and that under 160 ${\mu}{\textrm}{m}$ the wear volume decreased as load increased at the same slip amplitude.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.55-63
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• 1998

The fretting wear characteristics of Zircaloy-4 tube in light water were investigated experimentally. A fretting wear tester was designed to be suitable for this fretting test. This study was focused on the effects due to the combination of normal load, slip amplitude and number of cycles as the main factors of fretting. The results of this study showed that the wear volume increased abruptly at slip amplitude above 100$\mu$m, which is defined as critical slip amplitude of Zircaloy-4 tube in light water, and that under 160$\mu$m the wear volume decreased as load increased at the same slip amplitude.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.71-77
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• 1999

The fretting wear characteristics of STS304 steel in seawater were investigated experimentally. A fretting wear tester was designed to be suitable for this fretting test. This study was focused on the effects due to the combination of normal load, slip amplitude and number of cycles and corrosive environment as the main factors of fretting. The results of this study showed that the wear volume increased abruptly at slip amplitude between 70${\mu}{\textrm}{m}$~ 100${\mu}{\textrm}{m}$ by fracture of oxide layers but above that slip amplitude the wear volume increased steadily.

• Tribology and Lubricants
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• v.33 no.4
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• pp.168-186
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• 2017

This paper presents a wear analysis procedure for calculating the wear of journal bearings during the start-up and coast-down cycles of a motoring stripped-down single cylinder engine operating with a tilted shaft. In order to decide whether the lubrication state of a journal bearing is in the mixed-elasto-hydrodynamic lubrication regime, we utilize lift-off speed and MOFT (most oil film thickness) under mixed-elasto-hydrodynamic lubrication regime at the corresponding aligned shaft. We formulate an equation for the modified film thickness in a misaligned journal bearing considering the additional wear volume described in Part I of this study. For this, we use the calculation results of the degree of misalignment and tilting angle obtained after finding the eccentricities of the two bearings supporting the crankshaft of a single cylinder engine. In this Part II, we calculate the wear of journal bearings using the fractional film defect coefficient, the asperity load sharing factor, and the modified specific wear rate for the application of mixed-elasto-hydrodynamic lubrication regime. We show that the accumulated wear volume after turning the ignition switch on and off once, increases to ${\sigma}=39{\mu}m$ and then decreases from ${\sigma}=39{\mu}m$ with increasing in surface roughness.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.302-307
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• 2004

The major flow-induced vibration mechanisms such as fluid-elastic and turbulence excitation can cause the various types of wear of the steam generator tubes in unclear power plant. It is generally accepted that the tube wear due to vibration is affected by the presence of gap clearance between tube and support plate. Connors showed that the tube wear depth could be estimated by using the relationship between wear volume and sliding distance for contact time. Au-Yang predicted the wear depth by using the nonlinear characteristics of normal work rate to contact time. In this study the effect of gap size on the steam generator tubes wear is analyzed by deriving the wear depth versus normal work rate relationship from these previous results.