• 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.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.391-392
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• 2006

Sintered materials have been applied widely in Valve Seat Inserts (VSI). The amount of wear on VSIs increases when used in gas (LPG, CNG) engines because of their dry environments. In this paper, two newly developed high performance VSI materials for gas engines are introduced. These materials applied new techniques, which are both high performance hard particle and new distribution method of solid lubricant, to increase wear resistance.

• Journal of Korea Foundry Society
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• v.20 no.4
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• pp.240-246
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• 2000

Surface layer properties such as composition, phase, hardness, and oxide layer condition are very important if the main failure mechanism of metals is wear. Generally, stable and dense oxide layers are known to decrease the wear rate of metals by prohibition of metallic junction occurred between bare metals. Addition of Si above 4 wt% to DCI(Ductile Cast Iron) is reported to enhance the significant oxidation resistance by forming the silicon-rich surface layer which inhibits further oxidation. And addition of up to 2 wt% Mo to high Si ductile iron produces significant increases in high temperature tensile strength, creep strength, thermal fatigue resistance and oxidation resistance. High pressure wear characteristics of unalloyed DCI(Ductile cast Iron), 4.46 wt% Si ductile iron, 4.3 wt% Si-0.52 wt% Mo ductile iron were investigated through unlubricated pin-on-disc wear test. Wear test was carried out at speed of 23m/min, under pressure of 3 MPa and 3.3 MPa. Wear surfaces of each specimen were observed by SEM to determine the wear mechanism under high pressure wear condition. Addition of Si 4.46 wt% severely deteriorated wear property of ductile iron compared to unalloyed DCI. But combined addition of Si 4.3 wt%andMo0.52wt%decreasedthefrictioncoefficient(${\mu}$)ofductileironsandremarkablydelayedthemild-severeweartransition.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.6
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• pp.895-900
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• 2013

Several plasma spray and metallurgical surface coatings such as $Al_2O_3$, $Cr_2O_3$, WC-Ni, and chromizing coating have been examined for their application in environments with high temperature, wear, and corrosion. The chromizing coating is different from others coatings in the manufacturing process the surface. These coatings' characteristics were tested experimentally, and the results were compared. WC-Ni shows good performance against thermal barrier, wear, and corrosion and is one of the best candidates for the environment considered herein. These coatings were studied for their application in the steel manufacturing industry. The most commonly required functions in this industry are thermal and wear resistance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.478-483
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• 2011

Cast mold has low wear-resistance comparing with other alloyed molds which result in lower production rate and high cost of products. Recently, various weld methods are being applied to increase the wear-resistance of molds and to extend mold life. Among them, nickel alloy weld process increases the hardness irrelevant to its machinability and creates very uniform structures. In addition, it causes better wear-resistance and reduces shrinkage defects. In this paper, we analyze the mold surface cracks welded by nickel alloy and propose the methods to improve the mold surface and its wear-resistance. It has been found that nickel alloy weld does not affect the inside crack of mold but has an influence on the surface crack seriously. Results show that the start and growth of fatigue cracks have been delayed about 3 times and reduced approximately 75%, respectively, and the mold surface cracks are decreased about 5.7 times.

• Journal of Welding and Joining
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• v.19 no.5
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• pp.506-511
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• 2001

Weld overlay has been developed to improve the property of material surface which is used in the severe environment. Weld overlay is the process which uses an arc heat and welds different composition of alloy on the substrate for the improvements of heat resistance and wear resistance. Weld overlay has a lot of advantages which are high hardness, good processing efficiency, easy controlling of layer thickness, good quality and low cost. In this study, weld overlay was performed by MAG welding on the base metal(SS400) with filler metal which contain composite powders(Cr+C+Mn+Mo+NbC) and solid wire(JIS-YGW11). Characterization of hardness and wear resistance were analyzed by EDS, EPMA, XRD and observations of microstructure were performed to investigate characteristics of overlays. The experimental results of overlaid specimens manufactured with Cr+C+Mn+Mo+NbC powders were obtained as fellows. ${\alpha}-phase$, M(Fe, Cr)3C and NbC of overlays were increased with decreasing the wire feed rates and increasing powder feed rates. Also the hardness of overlays were increased and the specific wear were decreased.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.51-56
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• 2015

This paper presents an investigation of abnormal wear of a contact jig between a nail and a nail fixture in electric resistance welding. To perform an analysis on the abnormal wear phenomenon, several methods are provided. Based on the theory of electric resistance welding, are analyzed. Using microscopic analysis, surface craters are observed. In the measurement of the electric current flow in the nail fixture, the current flow distribution is measured. From several analyses, the cause of abnormal wear in the contact jig is measured using the electric discharge of high current density at the inflow point of the electric supply to the nail fixture. An alternative shape for normal wear is proposed.

• Transactions of Materials Processing
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• v.32 no.3
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• pp.114-121
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• 2023

During rolling, rolling mill rolls endure wear when shaping metal billets into a desired form, such as bars, plates, and shapes. Such wear affects the lifespan of the rolls and product quality. Therefore, in addition to rigidity, wear performance is a key factor influencing the performance of rolling mill rolls. Conventional methods such as casting and forging have been used to manufacture rolling mill rolls. However, powder alloying methods are increasingly being adopted to enhance wear resistance. These powder manufacturing methods include atomization, canning to shape the powder, hot isostatic pressing to combine the powder alloy with conventional metals, and various wear performance tests on rolls prepared with powder alloys. In this study, numerical simulations and experimental tests were used to develop and elucidate the wear analysis mechanism of rolling mill rolls. The wear characteristics of the rolls under various rolling conditions were analyzed. In addition, experimental tests (wear and surface analysis tests) and wear theory (Archard wear model) were used to evaluate wear. These tests were performed on two different materials in various powder states to evaluate the different aspects of wear resistance. In particular, this study identifies the factors influencing the wear behavior of rolling mill rolls and proposes an analytical approach based on the actual production of products. The developed wear analysis mechanism can serve the future development of rolls with high wear resistance using new materials. Moreover, it can be applied in the mechanical and wear performance testing of new products.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.6
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• pp.405-411
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• 2000

The effects of added elements, such as Co or Nb, on wear properties of high speed steel by powder metaliurgy(PM-HSS) had been eluminated in auther's previous paper. In addition, it is generally known that the wear properties of materials have been influenced by heat-treating conditions as well. Therefore, a study has been done to clarify the effects of heat-treating conditions on wear properties of PM-HSS. The wear tests have been performed under the same conditions as the previous paper using heat-treated PM-HSS(5%Co-1%Nb) with different quenching and tempering temperatures. The result of this paper shows that wear resistance of PM-HSS is improved with relatively high quenching temperature. However, tempering temperature is not sensitive to the wear resistance in the range of high quenching temperature. It may be deduced by the fact that the shear strength of matrix by strengthening mechanisms due to not only the quenching aging but also dispersion-hardening is improved.

• Proceedings of the Korean Vacuum Society Conference
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• 1995.06a
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• pp.151-151
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• 1995

Nitrogen implantation process has been applied for improvement of wear resistance of Z Zircaloy-4 fuel cladding materials. Nitrogen was implanted at 120 ke V to a total do range of 1xHP ions/cm2 to 8xlO17 ions/cm2 at various temperatures of 298"C to 676"C. The m microstructure changes by nitrogen implantation were analyzed by using TEM, XRD 뻐d A AES, cmd then wear behavior was evaluated by ball-on-disc wear testings at various loads a and sliding velocity under unlubricated condition. Nitrogen implantation produced ZrNx nitride above 4.37x1017 ions!cm2 as well as heavy d dislocations, which enhanced microhardness of the implanted surface of up to 900 Hk from 2 200 Hk of unimplanted substrate. Hardness was also found to be increased with increasing i implantation temperature and enhanced up to OOOHk at 620 "C. the wear resistance was g greatly improved with increasing total ion do않 as well as implantation temperature. The effective enhancement of wear resistance at high dose and tem야ratures is believed d due to significant hardening associated with high degree of precipitation of Zr nitrides and g generation of prismatic dislocation I$\infty$ps.infty$ps.