• KSTLE International Journal
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• v.4 no.1
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• pp.31-36
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• 2003

Sliding and impact/sliding wear test in room temperature air and water were performed to evaluate the effect of spring shapes on the wear mechanism of a fuel rod. The main focus was to quantitatively compare the wear behavior of a fuel rod with different support springs (i.e. two concaves, a convex and a flat shape) using a ratio of wear volume to worn area (De)-The results indicated that the wear volumes at each spring condition were varied with the change of test environment and loading type. However, the relationship between the wear volume and worn area was determined by only spring shape even though the wear tests were carried out at different test conditions. From the above results, the optimized spring shape which has more wear-resistant could be determined using the analysis results of the relation between the variation of De and worn surface observations in each test condition.

• Tribology and Lubricants
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• v.20 no.1
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• pp.7-13
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• 2004

High strength steels are widely used as tribo-materials in the field. Previous study revealed that for mild steel, the states of strain on the worn surface measured by X-ray diffraction has a good relationship with the state of wear. The objective of this study is to identify the relationship between the state of strain on the worn surface and the state of wear in high strength steels. Sliding wear tests were carried out using several hardened steels. X-ray diffraction tests were conducted to analyze the state of strain on the worn surface during wear. The experimental results indicated that the state of strain on worn surface in the hardened steel shows the same tendency as in the mild steel. It is clear that change of half value width on the worn surface as a function of sliding speeds is broadly similar in shape to wear characteristics curve and its magnitude has a good relationship with the wear rate at two different wear modes in the hardened steel.

• KSTLE International Journal
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• v.4 no.2
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• pp.47-51
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• 2003

Sliding wear tests have been carried out in room temperature air and water in order to compare the wear resistance of Zr-xNb-xSn alloys of various alloying elements (Nb and Sn). The main focus was to quantitatively compare the wear properties of the recently developed Zr-xNb-xSn alloys with the commercial ones using the evaluation parameters of the wear resistance with the consideration of the worn area. As a result, the recently developed alloys had a similar wear resistance compared with the commercial ones. The dominant factor governing the wear resistance was the protruded volume of the wear debris that was formed on the worn area in the air condition, but the accommodation of the plastic deformation on the contact area in water. In addition, the worn area size appeared to be very different depending on the tested alloys. To evaluate the wear resistance of each test specimen, the ratio of the wear volume or the protruded volume to the worn area ($D_e$ or $D_p$) is investigated and proposed as the evaluation parameters of the wear resistance.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.256-261
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• 2004

To evaluate the effect of spring shape on the fretting wear of nuclear fuel rod, sliding wear tests were performed using three kinds of space grid springs in room temperature air and water. With increasing slip amplitude, wear volume of each spring gradually increased. It is apparently shown that spring with convex shape had a relatively high wear resistance compared with concave shape springs. It is suggested that the ratio of the wear volume to the worn area can be suggested as an efficient and valid parameter to evaluate the wear resistibility of a fuel grid spring.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.233-239
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• 1999

The feasibility of an ultrasonic technique using a pulse-echo method of normal-incident compressional waves was evaluated for its sensitivity to the worn surface and near surface damage due to wear. Worn surfaces were generated at various oscillation frequency under a given load and amplitude and these surface were in situ monitored using a ultrasonic wave detection system. Analysis of the ultrasonic waves received from the worn surface revealed a close relationship between the surface and near-surface damage and the maximum echo-amplitude of the compressional waves. The ultrasonic technique was successful in assessing the level of severity of the worn surface in real time during the wear process. It is also shown that the wear depth can be easily measured by the calculation of change of the specimen thickness based on the wave speed measured for the specimen medium.

• Tribology and Lubricants
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• v.16 no.5
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• pp.351-356
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• 2000

The feasibility of an ultrasonic technique using a pulse-echo method of normal-incident compressional waves was evaluated for its sensitivity to the worn surface and near surface damage due to wear. Worn surfaces were generated at various oscillation frequency under a given load and amplitude and these surface were in situ monitored using a ultrasonic wave detection system. Analysis of the ultrasonic waves received from the worn surface revealed a close relationship between the surface and near-surface damage and the maximum echo-amplitude of the compressional waves. The ultrasonic technique was successful in assessing the level of severity of the worn surface in real time during the wear process. It is also shown that the wear depth can be easily measured by the calculation of change of the specimen thickness based on the wave speed measured for the specimen medium.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.313-323
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• 2003

The sliding wear behaviors of Zircaloy-4 nuclear fuel rod were investigated using two support springs with convex and concave shapes in room temperature air and water. The main focus is to compare the wear behavior of various test variables such as slip amplitude, environment, contact contours with different spring shape and a number of cycles. The results indicated that wear volume and maximum wear depth increased with slip amplitude in both air and water, but their trends tended to change according to the spring shapes and test environments. In air condition, the wear volume was controlled by wear debris behavior generated on worn surface. As a result, final wear volume and maximum wear depth decreased if a ratio of protruded wear volume to worn area $(D_p)$ would be saturated to specific value. This is because wear particle layer could accommodate large strain by accumulating and transforming wear particle layer. However, in water condition, metal-to metal contact was more dominant and wear volume was greatly affected by changed mechanical behavior between contact surfaces since wear debris should be generated after repeated plastic deformation and fracture. After wear test, worn surfaces were examined using optical microscope and SEM and details of wear mechanism were discussed using a ratio of wear volume to worn area $(D_e)$ at each test condition.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.19-24
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• 1999

Understanding of wear mode and prediction of wear rate of parts in sliding contact are very important in field of meterial design relating with wear resistant. This paper has been undertaken to analyze the possibility of elucidation of wear mode and prediction of wear rate for annealed steel in sliding contact using the X-ray diffraction. The sliding wear test with various velocities using pin-on-disc machine and the X-ray diffraction test on the worn surface have been carried out. The results have been shown that the magnitude of residual stress and half-value breadth on the worn surface have a good correlation with wear mode. The difference between before and after test of half-value breadth on worn surface has been shown to be exponential relation with wear rate in the same wear mode.

• Journal of the Korean Ceramic Society
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• v.30 no.12
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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.

• Journal of the Korea Fashion and Costume Design Association
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• v.22 no.1
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• pp.61-71
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• 2020

This study looks at 'Corporate Social Responsibility' which is required for the fashion industry and brands in modern times. The American fashion brand known for its corporate social responsibility activities, 'Patagonia' is the case study for this research. The purpose of this study is to make suggestions to eco-friendly, outdoor and casual apparel fashion brands that want to introduce corporate social responsibility programs by considering the case of Patagonia's "Worn Wear" campaign. The method of this study was to review corporate social responsibility, previous studies on Patagonia, and literature, such as domestic and foreign media, Patagonia's official homepage, specialty publications, and media. The study concerning corporate social responsibility is focused on Patagonia's "Worn Wear". Worn Wear is Patagonia's system that repurchases and repairs products from Patagonia's own consumers. The study found that the well known corporate social responsibility led to increased sales. Patagonia's social responsibility activities are thought to be part of the brand identity that goes beyond marketing. In the Worn Ware case, repurchasing products from consumers and reselling them or reprocessing them resulted in increased sales, increased consumer engagement, and higher brand attention. The suggestion for a fashion company or brand in a category similar to Patagonia that is looking to engage in corporate social responsibilbty is to adopt and continue a campaign that 'consists of a successful marketing image, connecting memories and new experiences, separated shopping channels while diversifying the creation of distribution and contact channels'.