• 한국세라믹학회지
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• 제39권9호
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• pp.851-856
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• 2002

산화몰리브덴($MoO_3$)이 첨가된 산화크롬 용사코팅층을 제조하여 산화몰리브덴의 첨가에 따른 고온(450$^{\circ}C$)에서의 플라즈마 용사코팅층에 마찰, 마멸특성을 조사하였다. 마찰, 마멸 특성에 대한 실험을 위하여 왕복동 마멸시험장치를 사용하였다. TEM을 이용하여 코팅층의 미세 구조와 각 상들의 조성을 살펴보았다. 분석 결과에 의하면 산화몰리브덴이 입계로 분산되어 있어 코팅층의 경도와 밀도의 증가가 발생하였다. 마멸시험후 마멸면의 물리적 변화와 화학적 조성의 변화를 SEM와 XPS를 통하여 살펴보았다. 산화몰리브덴이 첨가된 코팅층에서 마찰계수의 감소를 관찰할 수 있었다. 산화몰리브덴이 첨가된 코팅의 마멸된 표면에 마찰, 마멸에 유리한 보호막의 형성이 광범위하게 일어남을 알 수 있었다. 이러한 보호막에 몰리브덴이 산화몰리브덴의 형태로 존재하는 것을 XPS 분석을 통하여 알 수 있었다. 보호막에 산화몰리브덴의 존재가 마찰계수를 감소시키는 것으로 생각된다.

• 한국군사과학기술학회지
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• 제20권1호
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• pp.12-17
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• 2017

In this paper, causes of wear on high pressure seals for suspension are analyzed, and the result of reproduction test and verification on improved design are described. First, by performing the observation of worn surfaces and its failure analysis, the primary cause of wear on the seals are analyzed. The result of analysis shows that the main failure mechanism of wear is a fatigue wear, and test criteria for failure reproduction are set up with consideration for frequency condition, surface roughness and pressure. Durability comparison test on the condition of low amplitude and high frequency is carried out. And, it is found that the durability of wear on seals by increasing hardness of cylinder and managing for surface roughness is enhanced.

• 한국의류산업학회지
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• 제19권6호
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• pp.777-785
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• 2017

The MICE industry is a new industry that combines corporate meetings, intensive tours, conventions and exhibitions. The convention (the international conference itself) is a conception born from the interpretation of multiple industries such as conferences, incentive tourism, exhibitions and fairs. It is therefore necessary to develop products that can contribute to the revitalization of the MICE industry. We will participate in globalization era trends by developing original design with unique color sense as well as traditional beauty and elegance that can represent the Korean Wave in order to develop high value-added fashion cultural products. We examine the formative characteristics of Chogakbo and apply them to the harmony of geometrical characteristics and colors. The morphological characteristics and sewing method of the Korean traditional 'fo' were also used for shirt designs. It is a fashion cultural product that applies to the Korean Cheokagbo design as well as maintains a basic aloha shirt design that can be worn by everyone (regardless of gender and age) to make it globally acceptable. We used a simple and interesting geometric configuration of the surface represented by the surface composition of the patchwork as well as proposed a design costume by 3D clothing simulation work. The research results can be used as basic data for the domestic fashion market and cultural goods market.

• 박물관보존과학
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• 제10권
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• pp.21-27
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• 2009

죽제조문필통은 직경 80mm정도의 통대 2개를 맞붙이고, 바닥에는"∞"모양의 가중나무 판재를 붙였다. 그리고 외부면에는 용과 구름, 사슴과 소나무 문양이 음·양각 기법으로 각각 정교하고 힘차게 조각되었다. 이 죽제조문필통은 일부가 파손, 결실 그리고 분해된 상태였지만 이번 보존수리를 통해 그 원형을 되찾게 되었다. 결실부에는 토분·호분·아교를 혼합하여 복원재료로 이용하였고, 원형을 되찾은 후 접합부분 안쪽에 얇은 비단 천을 부착하여 터짐을 방지하였다. 또한 복원된 표면은 옻칠을 이용해 고색처리를한것등 전통적인 재료와 수리기법을 응용한 가역적인 처리에 중점을 두었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.66-74
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• 2004

The sliding wear behavior of $ZrO_2-22wt\%MgO\;(MZ)\;and\;ZrO_2-8wt\%Y_2O_3\;(YZ)$ deposited on a casting aluminum alloy with bond layer (NiCrCoAlY) by plasma spray against an SiC ball was investigated under dry test conditions at room temperature. At all load conditions, the wear mechanisms of the MZ and the YZ coatings were almost the same. The wear mechanisms involved the forming of a smooth film by material transferred on the sliding surface and pullout. The wear rate of the MZ coating was less than that of the YZ coating. With an increase normal load the wear rate of the studied coatings increased. The SEM was used to examine the sliding surfaces and elucidate likely wear mechanisms. The EDX analysis of the worn surface indicated that material transfer was occurred from the SiC ball to the disk. It was suggested that the material transfer played an important role in the wear performance.

• 대한기계학회논문집
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• 제19권3호
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• pp.705-712
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• 1995

The wear characteristics and wear mechanisms in TiN coating deposited on high speed steel and alloy tool steel by ion plating were investigated. Pin on V-block wear tester was used for a wear test method. The specimen was composed of three kinds of high speed steel and alloy tool steel which had different hardness by changing the heat treating condition. Three kinds of coating thickness were also applied to each specimen. Microscopic observation of worn surfaces was made by SEM. The scratch test of coating surface by the ion plating showed that critical load to break the coating interface was greater than 50N. The critical load increased with both substrate hardness and coating thickness. The wear resistance of TiN coated high speed steel became 10 times greater than that of non-coated ones. SEM observation showed that leading edge of contact was compressive and trailing edge was under maximum tensile stress and then surface cracking broke out perpendicular to sliding direction.

• 한국주조공학회지
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• 제24권2호
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• pp.108-114
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• 2004

$Al_2O_3$, SiC reinforced Al matrix composites were fabricated by centrifugal spray casting method and their wear resistance characteristics have been studied. Particles are generally uniformly distributed in the microstructure of as-cast specimens. In order to investigate the effect of secondary deformation, hot rolling was performed for each specimen of pure Al matrix composites with a reduction of 10, 20, 30, 40 and 50% at $400{\sim}500^{\circ}C$, respectively. Microstructure of specimen showed that particle distribution density and hardness increased because of increasing of reduction ratio. Wear test with a various sliding velocity of 1.98, 2.38, 2.88 and 3.53m/sec showed that the wear resistance characterization of composite improved remarkably compared to the normal alloy and performs without reinforced particles. Microstructural observation for the worn surface of pure Al specimens without particles showed that a change in wear mechanism seemed to separate layer by surface fatigue. In other case of Al composite reinforced with $Al_2O_3$ and SiC, the grinder type of wear mechanism was shown.

• Journal of Welding and Joining
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• 제14권3호
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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.

• Journal of Welding and Joining
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• 제18권5호
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• pp.105-111
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• 2000

The wear behavior of thermal sprayed AlSiMg-40TiC composite coatings were studied as a function of load and sliding velocity under unlubricated conditions. Experiments were performed using a block-on-ring(WC-6wt%/Co, Hv 1500) type. The tests were carried out a various load(30∼ 125.5N) and sliding velocity(0.5∼2.0m/s). Three wear rate regions were observed in the AlSiMg-40TiC composite coatings. The wear rate in region I at low load (less then 8N( were less than 1×{TEX}$10^{-5}${/TEX}㎣/m. Low wear rates in region I resulted from the load-bearing capacity of TiC particles. The transition from region I to II occurred when the applied load exceeded the fracture and pull-out strength of the particles. The TiC fractured particles trapped between the specimen and the counterface acted as third-body abrasive wear. The subsurface layer worn surface in region II was composed of the mechanically mixed layer (MML). The wear rate increase abruptly above a critical load (region III). The high wear rate in region III was induced by frictional temperature and involves massive surface damage.

• 한국안전학회지
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• 제27권3호
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• pp.9-14
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• 2012

The objectives of this study were to compare the results of HSL (Health and Safety Laboratory) ramp test with perceived sense of slip onto the several different floor surfaces under contaminated conditions. There are a variety of approaches from biomechanical measurements to psychophysical test and human perception. However, controversies over these approaches still remain. Some widely accepted methods need to be improved. AHP (Analytic Hierarchy Process) was used to evaluate the perception of slipperiness of seven different floor surfaces under the contaminated condition with glycerol solution. Twelve subjects worn same footwear and walked with self-selected step and cadence along the test floors. The angle of inclination obtained for water wet condition using 5 l/min with HSL ramp test was compared to perception of slipperiness. The surface roughness ($R_z$) related very well both AHP (r=0.95) and ramp test (r=0.92). The high significant correlation (r=0.90) was found between AHP and HSL ramp test.The HSL ramp test values (Coefficient of Friction, COF) according to subjective evaluation were divided into two categories. There were high correlations between test results (subjective evaluation, HSL ramp test) and surface roughness in Rz. Perception rating obtained with AHP showed a high correlation with COF obtained with HSL ramp test.