• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.35-43
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• 2004

Skid resistance is an important factor that control braking distance and secure safety by preventing slipperiness between tire and pavement surface. Decrease of skid resistance at wet condition may cause fatal traffic accidents. Dirt materials such as sand and do-icings on the road surface also can be a factor for decrease skid resistance. This study makes an investigation into influence of skid resistance between varied cement concrete pavements about surface texturing method(transverse tining, longitudinal tining, exposed aggregate surface texturing method) and wearing condition of pavement surface texture(new constructed pavement's surface, wore pavement's surface) using accelerate concrete pavement wearing tester when remains of dirt material are obtained between tire and road surface on PCC pavement. As dirt material on road surface of concrete pavement, sand, calcium chloride and old oil were used with different amount of each cases.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1988.06a
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• pp.28-30
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• 1988

윤활시스템에서 마모는 상대적인 운동을 하는 두 물체사이에서 표면상태, 접촉조건 및 분위기등의 제요소들에 의해 발생되며, 형태학적으로 scuffing, scoring, pitting 및 fretting 등으로 분류된다. 윤활조건의 특성에 따라 미끄럼 접촉에서는 mild wear, severe wear로 구분되며, 이들의 마모 생성기구의 차이는 접촉상대속도, 하중 및 표면조도등의 정도에 기인된다. mild wear에서 severe wear 영역으로 전이될 때의 가혹한 조건에서 생성되는 마모현상을 scuffing wear라 하며, 이는 접촉면에서의 표면돌기의 직접접촉에 의한 cold welding 현상, 즉 local welds의 특성을 지닌 마멸형태로 정의한다. 이의 생성은 접점간의 하중 및 미끄럼 속도가 증가됨에 따라 온도상승에 기인되어 순간적으로 발생된 마찰열이 그 원인이 있으며, 기어, cam 및 tappet, 피스톤링 및 실린더 라이너 등의 마멸현상이 대표적인 예이다.

• Tribology and Lubricants
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• v.7 no.2
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• pp.28-35
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• 1991

3원통/링 마모시험기를 사용하여 윤활유 공급하에서 미끄럼 마모시험을 수행하였다. 엔진유에 첨가되는 대표적 첨가제인 ZDDP, 청정제, 분산제의 첨가제 3종과 모델 산호물로서 유성제인 스테아린산을 선택하여, 그 배합유의 마모방지특성을 조사하였다. 청정제 및 분산제 각각의 첨가에 의해 마모방지특성은 향상되었으나, 청정제 및 분산제를 동시에 첨가할 경우 마모방지성능의 향상효과는 없어졌다. 또한, 모델산화물인 스테아린산의 첨가로 인하여 ZDDP의 마모방지작용은 나빠지나, 청정분산제가 그 악영향을 억제하는 작용을 한다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.184-189
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• 2002

기계부품 및 구조물의 상호접촉면이 미소변위에 의해 상대운동을 할 때 접촉면에서는 마모가 발생하고 이러한 마모현상은 당해 구조물의 안전성을 심각하게 위협하는 결과를 초래하게 된다. 이러한 마모 현상에 대한 근래의 연구동향으로는 $Engel^{(1.2)}$ 이 충격(impact)에 의한 마모에 대해, 그리고 $Waterhouse^{(3)}$ 는 미끄럼(sliding) 마모에 대해 연구한 바 있다. 원자력발전소의 증기발생기(steam generator) 내에서 1차측의 세관(tube)과 2차측에 속하는 지지물(supporter) 또는 방진대(antivibration band) 사이에서 세관의 진동으로 인해 지지물과 충돌을 일으키고 충돌 횟수가 누적되면 세관의 마모로 이어져 결국 세관의 건전성은 침해받게 된다.(중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.439-445
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• 2005

The tribological properties of ceramics are very important in the application to engineering ceramic parts such as seal rings, pump parts, meter parts, and so on. In this study, the effects of each other purity on the mechanical and tribological properties of alumina and zirconia ceramics were investigated. Sliding distance, sliding speed, contact load. friction coefficient, the amount of worn out material at a certain time, and the prepared composites were measured. Crystalline phases and microstructure were examined with XRD and SEM. We obtained the good properties of friction coefficient and wear resistance at the purity 99.7$\%$ of alumina. However, The purity 95$\%$ were great at the wear amount of worn out material.

• Journal of the Korea Institute of Building Construction
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• v.5 no.1 s.15
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• pp.53-61
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• 2005

The purpose of this study presents useful data on the choice or development of floor covering from slip viewpoint by examining closely the impact of the changes in sliding experiments due to the wear of floor covering by walk. The result of wear practical test per ten thousand walks enforces some kind of popular floor covering and measure of coefficient of slip resistance as follows: (1) When surface of floor covering is in the state of wet, the degree of wear doesn't affect greatly in slip. (2) When surface of floor covering is in dry and clean state, most floor coverings have the tendency to lower the coefficient of slip resistance with the amount of walk on it. (3) Change in the tendency of slip resistance by wear appeared mainly due to the differences in the state of floor covering and organic floor covering appeared to have great reduction of coefficient of slip resistance than the inorganic ones. (4) According to the result of investigation on changes in tendency of coefficient of slip resistance due to the increase in the number of walk and if two hundred thousand walks were done, regardless of surface shape or kind of site, etc, the safety of floor covering, in slip viewpoint, greatly reduces.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1992.11a
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• pp.63-76
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• 1992

금속재료에 경도가 큰 TiN을 코팅하면 우수한 내마모성능을 얻을 수 있기 때문에, 이 TiN 코팅은 절삭공구나 금형등의 수명을 향상시킬 수 있는 방법이라고 기대를 모으고 있다. 특히 최근에는 물리증착법이 개발되어, 비교적 낮은 온도에서 연화되는 재료에도 코팅할 수 있게 됨에 따라, 엔드밀, 드릴등의 고속도강계의 절삭공구나 금형등의 수명을 크게 향상시킬 수 있는 방법으로 이 TiN코팅이 커다란 주목을 받게 되었다. 그러나 이 TiN 코팅이 미끄럼중에 어떻게 마모되는지는 아직도 잘 알려지지 않고 있다. 본 연구의 목적은 고속도강에 코팅된 TiN의 마모기구를 실험적으로 관찰하여 규명하는 것이다.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.62-68
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• 2000

Ultra thin TiN films (50∼700nm thickness) were deposited on AISI 304 stainless steel substrates using a reactive DC magnetron sputtering deposition process to investigate their wear and friction properties. Dry sliding wear tests of the films were carried out against hardened steel and alumina counterparts using a pin-on-disk type wear tester at room temperature. Variation of friction coefficient was measured as a function of film thickness, load, sliding speed and roughness of the substrate. Worn surfaces of the film were examined by a scanning electron microscope. Wear resistance of the TiN film increased with the increase of the film thickness. The TiN film showed relatively high wear resistance in spite of its ultra thin thickness when it is mated by the steel counterpart, while it showed poor wear resistance with the alumina counterpart. The good wear resistance with the steel counterpart was explained by the formation of oxide layers on the film surface and sound interface character between the ultra thin film and the substrate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1349-1354
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• 2013

Sealing structure to prevent flowing hot gas into the driving device, located between the driving shaft and the liner of On-Off valve for controlling the hot gas flow path was studied. Wear occurs due to the constant movement of the driving shaft controlled by actuator on graphite as the sealing material. In this paper, the dynamic wear behavior in high temperature of graphite(HK-6) to be used as sealing material was evaluated. Reciprocating wear test was carried out for the graphite(HK-6) to the relative motion between shaft materials(W-25Re). The results of friction coefficient and specific wear rate according to contact load, sliding speed at room temperature and $485^{\circ}C$ considering the actual operating environment were evaluated. Through the SEM analysis of the worn surface, third body as lubricant films were observed and lubricant effect of third body was considered.

• Tribology and Lubricants
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• v.36 no.3
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• pp.117-123
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• 2020

In this study, the effect of the pre-mild wear mode test condition on the subsequent severe wear behavior of carbon steel has been investigated when the wear mode is varied according to the sliding speed change during sliding contact. Two sliding speeds of 0.3 m/s and 3 m/s for the mild wear mode test have been chosen and a sliding speed of 1 m/s for the severe wear mode test. A mild wear mode test at two different sliding speeds has been carried out during the severe wear mode test and total sliding distance of the mild wear mode test has been changed at this time. As a result, it could be found that the wear rate of carbon steel under the severe wear mode test after performing a pre-mild wear mode test is significantly reduced, compared with that before performing. However, its wear rate was slightly higher than that under the mild wear mode test. Oxides produced during the pre-mild wear mode test have been found to play a significant role in reducing the wear rate under the subsequent severe wear mode test. In particular, it was found that the effect of a pre-mild wear mode test performed at the sliding speed of 3 m/s has more rapid and the reduction in the wear rate was greater than thst at the sliding speed of 0.3 m/s.