• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.149-152
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• 2006

Dry sliding wear behavior of low carbon dual phase steel, of which microstructure consists of hard martensite in a ductile ferrite matrix, has been investigated. The wear characteristics of the dual phase steel was compared with that of a plain carbon steel which was normalized at $950^{\circ}C$ for 30min and then air-cooled. Dry sliding wear tests were carried out using a pin-on-disk type tester at various loads of 1N to 10N under a constant sliding speed condition of 0.2m/sec against an AISI 52100 bearing steel ball at room temperature. The sliding distance was fixed as 1000m for all wear tests. The wear rate was calculated by dividing the weight loss measured to the accuracy of $10^{-5}g$ by the specific gravity and sliding distance. The worn surfaces and wear debris were analyzed by SEM, EDS and a profilomter. Micro vickers hardness values of the cross section of worn surface were measured to analyze strain hardening behavior underneath the wearing surfaces. The were rate of the dual phase steel was lower than the plain carbon steel. Oxidation on the sliding surface and strain hardening were attributed for the higher wear resistance of the dual phase steel.

• 한국진공학회지
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• 제7권1호
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• pp.59-65
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• 1998

13.56MHz를 사용하는 r.f.PACVD(Plasma assisted chemical vapor deposition)방법 으로 다층 다이아몬드상 카본(DLC)필름을 Si wafer기판 위에 합성하였다. 다층 DLC필름은 2.5$\mu$m두께의 순수한 DLC필름과 0.2$\mu$m두께의 Si이 함유된 Si-DLC필름으로 구성되었으 며, ball on disk type의 tribometer를 이용하여 대기 중에서 다층 DLC필름의 마모거동을 고 찰하였다. 표면층으로 합성된 Si-DLC필름내의 Si함량이 증가함에 따라 다층 DLC필름과 AISI52100 steel ball 사이에 0.1 이하의 낮은 마찰계수를 유지하는 기간이 증가하였다. 44,000cycle과 158,400cycle의 마모실험 후 측정된 다층 DLC필름의 마모율은 각각 $2.5\times10^{-8}\sim1.8\times10^{-7}\textrm{mm}^3$/rev.과 $7.1\times10^{-9}\sim1.8\times10^{-8}\textrm{mm}^3$/rev.로 나타났다. 158,400cycle의 마모실험 후 측정된 마모율은 내마모 특성이 우수한 DLC필름보다도 2배 정도 우수한 것으로 나타났 다. 마모시험에 의해 형성된 debris의 조성을 분석한 결과, 이런 낮은 마찰계수와 우수한 내 마모 특성은 steel ball의 wear 표면을 덮고 있는 Si oxide debris층의 형성에 따른 결과로 판단되었다. 또한, 이러한 steel ball의 wear scar표면에 형성된 debris층을 제거하여도, 새로 운 Si oxide debris층이 wear scar표면에 다시 생성되어 낮은 마찰계수를 유지하고 있었다.

• 한국항공운항학회지
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• 제23권1호
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• pp.62-66
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• 2015

In this paper, a fretting testing machine is developed using ball-on-flat test apparatus. Precise micro-slip motion is produced by a linear stage. A relative displacement between a ball and a flat specimen is measured with a laser displacement sensor. Dry friction tests are conducted with AISI 52100 steel balls and cold-rolled high strength steel plates at room temperature and ambient humidity. The evolution of the kinetic friction coefficient is determined. Comparison between measured friction coefficients and those found in the literature is then carried out. Fretting tests with an electro-deposited coating are employed at an amplitude of 0.05 mm. Slip regime is identified with slip ratio. It is demonstrated that a developed testing machine allows determining the friction coefficient under fretting condition.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.421-424
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• 2007

Dry sliding wear behavior of ultra-fine grained (UFG) plain low carbon dual phase steel, of which microstructure consists of hard martensite in a ductile ferrite matrix, has been investigated. The wear characteristics of the UFG dual phase steel was compared with that of a coarse grained dual phase steel under various applied load conditions. Dry sliding wear test were carried out using a pin-on-disk type tester at various loads of 1N to 100N under a constant sliding speed condition of 0.20m/s against an AISI 52100 bearing steel ball at room temperature. The sliding distance was fixed as 1000m for all wear tests. The wear rate was calculated by dividing the weight loss, measured to the accuracy of 10-5g by the specific gravity and sliding distance. The worn surfaces and wear debris were analyzed by SEM, EDS and profilometer. Micro-vickers hardness of the cross section of worn surfaces were conducted to analyze strain hardening underneath the contact surfaces. The wear mechanism of the UFG dual phase steel was investigated with emphasis on the unstable nature of the grain boundaries of the UFG microstructure.

• 소성∙가공
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• 제16권4호
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• pp.299-303
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• 2007

Dry sliding wear behavior of ultra-fine grained(UFG) plain low carbon dual phase steel, of which microstructure consists of hard martensite in a ductile ferrite matrix, has been investigated. The wear characteristics of the UFG dual phase steel was compared with that of a coarse grained dual phase steel under various applied load conditions. Dry sliding wear test were carried out using a pin-on-disk type tester at various loads of 1N to 100N under a constant sliding speed condition of 0.20m/s against an AISI 52100 bearing steel ball at room temperature. The sliding distance was fixed as 1000m for all wear tests. The wear rate was calculated by dividing the weight loss, measured to the accuracy of 10-5g by the specific gravity and sliding distance. The worn surfaces and wear debris were analyzed by SEM, EDS and profilometer. Micro-vickers hardness of the cross section of worn surfaces were conducted to analyze strain hardening underneath the contact surfaces. The wear mechanism of the UFG dual phase steel was investigated with emphasis on the unstable nature of the grain boundaries of the UFG microstructure.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.385-388
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• 2009

Dry-sliding-wear behavior of Fe-18Cr-l0Mn steel with various carbon and nitrogen contents was characterized, and the effect of carbon and nitrogen contents on the wear was investigated. Dry sliding wear tests of the steel were carried out at room temperature against an AISI 52100 bearing steel ball using a pin-on-disk wear tester. Applied wear loads were varied from 10 N to 100 N, and the sliding distance was fixed as 720 m. Worn surfaces and the wear debris of the steel were examined using an SEM to find out the wear mechanism. It was found that the Fe-18Cr-10Mn with both carbon and nitrogen exhibited superior wear resistance to the steel with only nitrogen. The wear resistance of the Fe-18Cr-10Mn-xC-yN alloy increased with the increase of the carbon content. The excellent wear resistance of the Fe-18Cr-10Mn-xC-yN alloy was explained by the increased strain-hardening capability with the interstitial atoms.

• 대한기계학회논문집A
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• 제27권3호
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• pp.335-342
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• 2003

In this study, the effects of oxide layer formed on the contact parts of TiN coated ball and steel disk in sliding are investigated. Also wear mechanism to from the oxide layer and the characteristics of the oxide layer formation are investigated. AISI 52100 steel ball is used for the substrate of coated ball specimens. Two types of coated ball specimens were prepared by depositing TiN coating with 1 and 4 ${\mu}{\textrm}{m}$ in coating thickness. AISI 1045 steel is used for the disk type counter-body. To investigate the effect of oxide layer on the contact parts of the two materials, the tests were performed both in air for forming oxide layer on the contact parts and in nitrogen environment to avoid oxidation. And to study the effects of surface roughness of counter-body, TiN coating thickness and contact load of sliding test on the characteristics of oxide layer formation on counter-body, various tests were carried out. From the results, the friction characteristics between the two materials was predominated by iron oxide layer that formed on wear track on counter-body and this layer caused the high friction. And the formation rate of the oxide layer on wear track increased as the real contact area between the two materials increased as the contact load increased, the TiN coating thickness decreased and the surface of counter-body smoothened.

• Tribology and Lubricants
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• 제27권6호
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• pp.308-313
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• 2011

본 연구에서는 수직 하중과 미끄럼 속도가 DLC (a-C:H)와 WC/C (a-C:H:W)의 마찰 특성에 미치는 영향을 파악하기 위해 ball-on-disk 형태의 마찰 실험 장치를 이용하여 실험을 수행하였다. 연구 대상 고체 윤활막인 DLC와 WC/C는 AISI 52100 steel ball의 표면에 증착되었으며, 상대 마찰면의 재질은 침탄 경화된 SCM 415 Cr-Mo steel이다. 실험은 상대 습도가 20~40 %이고 온도가 $16{\sim}24^{\circ}C$인 대기 분위기에서 다양한 미끄럼 속도 (0.1, 0.78, 1.56, 3.13, 6.25, 12.5, 25, 50, 100 mm/s) 및 수직 하중 (2.4, 4.8, 9.6 N) 조건에 대해 수행되었다. 실험 결과로 각각의 실험 조건에서의 DLC와 WC/C의 운동 마찰 계수를 얻었다. 실험 결과 DLC와 WC/C의 운동 마찰 계수는 미끄럼 속도가 증가할 수록 대체로 증가하였으며, 수직 하중에 관계없이 거의 일정한 값을 보였다. 그리고 동일한 실험 조건에서 DLC의 마찰 계수가 WC/C의 마찰 계수에 비해 대체로 낮은 값을 보였다.

• Tribology and Lubricants
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• 제18권4호
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• pp.260-266
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• 2002

In this study, the effects of oxide layer farmed on the wear tracks of TiN coated silicon wafer on friction and wear characteristics were investigated. Silicon wafer was used for the substrate of coated disk specimens, which were prepared by depositing TiN coating with 1 ${\mu}{\textrm}{m}$ in coating thickness. AISI 52100 steel ball was used fur the counterpart. The tests were performed both in air for forming oxide layer on the wear track and in nitrogen to avoid oxidation. This paper reports characterization of the oxide layer effects on friction and wear characteristics using X-ray diffraction(XRD), Auger electron spectroscopy(AES), scanning electron microscopy (SEM) and multi-mode atomic force microscope(AFM).

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.167-168
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• 2002

In this study, the effects of oxide layer formed on the wear tracks of TiN coated silicon wafer on friction characteristics were investigated. Silicon wafer was used for the substrate of coated disk specimens, which were prepared by depositing TiN coating with $1\;{\mu}m$ in coating thickness. AISI 52100 steel balls were used for the counterpart. The tests were performed both in air for forming oxide layer on the wear track and in nitrogen to avoid oxidation. This paper reports characterization of the oxide layer effects on friction characteristics using X-ray diffraction (XRD). scanning electron microscopy (SEM) and friction force microscope (FFM).