• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2122-2132
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• 1995

There are some cases which require to grasp the abrasion resistance property in the fields of the high-technology to be required the high specific strength and modulus. In this study, wear test with the various test temperature and velocity were performed in the SiCw/A16061 composite and A16061 matrix using the wear test machine of the ring-on-disc type. As the results, the friction and wear properties by various test temperature and velocity were examined. The worn surface has observed by scanning electron microscope in order to examine the wear mechanism.

• KSTLE International Journal
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• v.3 no.1
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• pp.54-59
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• 2002

It can be effective on failure diagnosis of oil-lubricated tribological system to analyze operating conditions with morphological characteristics of wear debris in a lubricated machine. And it can be recognized that results are processed threshold images of wear debris. But it is needed to analyse and identify a morphology of wear debris in order to predict and estimate a operating condition of the lubricated machine. If the morphological characteristics of wear debris are identified by the computer image analysis and the neural network, it is possible to recognize the friction condition. In this study, wear debris in the lubricating oil are extracted from membrane filter (0.45 ${\mu}m$) and the quantitative value fur shape parameters of wear debris was calculated through the computer image processing. Four shape parameters were investigated and friction condition was recognized very well by the neural network.

• Tribology and Lubricants
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• v.29 no.1
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• pp.19-26
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• 2013

Cu-matrix sintered brake pads and low-alloy heat-resistant steel are commonly applied to basic brake systems in high-energy moving machines. In this research, we analyzed the tribological characteristics to determine the influence of the air velocity between the disk and pad. At a low brake pressure with airflow, the friction stability was decreased as a result of the lack of tribofilm formation at the disk surface. However, there were no significant changes in the friction coefficient under any of the test conditions. The wear rates of the friction materials were decreased with an increase in the airflow velocity. As a result, the airflow velocity influenced the friction stability, as well as the wear rate of the friction materials and disk, but not the friction coefficient.

• Tribology and Lubricants
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• v.17 no.6
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• pp.459-466
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• 2001

In this study, the effects of oxide layer formed on the contact parts of TiN coated ball and steel disk on friction characteristics in various sliding conditions were investigated. AISI52100 steel ball was used for the substrate of coated ball specimens, which were prepared by depositing TiN coating with 1(m in coating thickness. AISI1045 steel was used for the disk type counter-body. To investigate the effect of oxide layer on the contact parts of two materials, the tests were performed both in air for forming oxide layer on the contact parts and in nitrogen environment to avoid oxidation. From the test results, the frictional characteristic between the two materials was predominated by iron oxide layer that formed on wear tract of counter-body and this layer caused friction transition and high friction. And the adhesive wear occurred from steel disk to TiN coated ball caused the formation of oxide layer on counter parts between the two materials.

• Tribology and Lubricants
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• v.11 no.5
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• pp.55-58
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• 1995

The effects of Ni contents in Cu base sintered friction material were studied. The contents of Ni were increased up to 9 wt% in the Cu-Sn matrix. The microstincture and tribological behavior of the friction material were examined. Pin on disk type of constant speed friction test rig were used to measure the friction and the wear rates. The results show that Ni addition increased the friction coefficients and decreased the wear rates of the materials. Relations between microhardness of the matrix and friction properties have been discussed. In addition optimum Ni content is recommended through the analysis of wear debris.

• Elastomers and Composites
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• v.55 no.3
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• pp.161-166
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• 2020

On the basis of the use of shoes, the outsole, which is mainly made of rubber, has various characteristics. The most important of these characteristics is abrasion resistance and friction. Generally, the abrasion resistance can be improved by adding more reinforcing filler such as silica to the rubber; however, the friction force drops. Owing to these problems, rubber having excellent abrasion resistance and rubber having excellent frictional force are blended. In this study, various characteristics, including wear resistance and friction, were evaluated by blending NBR/SBR or NBR/BR mixture with high wear resistance and CIIR with high friction. The CIIR was increased up to 60 phr, whereas the friction wear characteristics were rapidly changed in the NBR/CIIR blend ratio from 75:15 to 60:30.

• KSTLE International Journal
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• v.1 no.1
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• pp.12-20
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• 2000

Nano-wear and friction of carbon overcoated laser-textured and mechanically-textured computer hard disk were characterised after contact start/stop (CSS) wear test. Various analytical and mechanical testing techniques were employed to study the changes in topography, roughness, chemical elements, mechanical properties and friction characteristics of the coating arising from the contact start/stop wear test These techniques include: the atomic force microscopy (AFM), the continuous nano-indentation test, the nano-scratch test, the time-of-flight secondary ion mass spectroscopy (TOF-SIMS) and the auger electron spectroscopy (AES). It was shown that the surface roughness of the laser-textured (LT) bump and mechanically textured (MT) Bone was reduced approximately am and 7nm, respectively, after the CSS wear test. The elastic modulus and hardness values increased after the CSS test, indicating straining hardening of the top coating layer, A critical load was also identified fer adhesion failure between the magnetic layer and the Ni-P layer, The TOF-SIMS analysis also revealed some reduction in the intensity of C and $C_2$$F_59$, confirming the wear of lubricant elements on the coating surface.

• Tribology and Lubricants
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• v.36 no.6
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• pp.350-358
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• 2020

Hot stamping is an effective and suitable process widely used in automotive applications, though critical issues such as the transfer of the coating materials and build-up of these materials on tool surfaces have been encountered. Past researches figured out the resultant wear phenomenon using pin-on-disc and drawing (for example, strip drawing and deep drawing) methods to mimic the process and analyzed the wear behavior with respect to the influencing factors such as surface coating, load, and roughness. Although the pin-on-disc is a conventional and widely-used method, it presented a methodological limitation when simulating the hot stamping process by forming a new blank each time, and hence, a drawing-based friction method has been proposed and developed. Each drawing method applies loads in a different way, resulting in a different wear behavior. Notably, the deep drawing process is most similar to the hot stamping process compared to other drawing methods. In this paper we present a review of the friction testing methods mimicking the hot stamping process and the associated wear behavior. This can be helpful in presenting a step-by-step approach and different perspectives on the wear behavior in the hot stamping process.

• Polymer(Korea)
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• v.25 no.1
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• pp.133-141
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• 2001

The friction and wear properties of carbon-carbon composites made with different weight percent of $MoSi_2$ as an oxidation inhibitor were investigated using a constant speed wear test apparatus in an oxidation environment. The results indicated the carbon-carbon composites undergoing an abrupt transition of friction coefficient, from low-friction behavior(${\mu}$=0.15~0.2) during normal wear regime to the high-friction behavior(${\mu}$=0.5~0.6) during dusting wear regime at the frictional temperature range of 150~180${\circ}C$. The existence of temperature-dependent friction and wear regimes implied that the performance of specimen made with carbon-carbon composites was markedly affected by the thermal properties of the composites. The carbon-carbon composites filled with MoSi2 exhibited two times lower coefficient of friction and wear rate in comparison with the composites without $MoSi_2$. Especially, the composites containing 4wt% $MoSi_2$ filler showed a significantly improved activation energy for wear due to the reduction of both the porosity and powdery debris film formation on sliding surface when compared to those without $MoSi_2$.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.135-138
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• 2002

The purpose of this study is to investigate the lubricated wear properties of Saffil/Al, Saffil/$Al_2O_3/Al$ and Saffil/SiC/Al hybrid metal matrix composites fabricated by squeeze casting method. Wear tests were done on a pin-on-disk friction & wear tester with long sliding distance. The wear properties of the three composites were evaluated in many respects. The effects of Saffil, $Al_2O_3$ particles and SiC particles on the wear behavior of the composites under lubricated conditions were elucidated. Wear mechanisms were analyzed by observing the worn surfaces of the composites. The variation of coefficient of friction (COF) during the wear process was recorded by using a computer. Comparing with the dry sliding condition, all three composites showed excellent wear resistance when lubricated by liquid paraffin. Under intermediate load, Saffil/Al showed best wear resistance among them, and its COF value is the smallest. The dominant wear mechanism of the composites was microploughing, but microcracking also occurred for them to different extent.