• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 제35회 춘계학술대회
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• pp.240-247
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• 2002

The rolling wear behavior of SM55C is investigated under lubrication. This is a comparative tribological behavior of heat treatment effect for SM55C. Rolling wear test method is used for Ball-on-disk type. Specimens can be classified into two main groups: as-annealing and non-annealing. As result of wear behavior, flanking initial time of non-annealing specimen keep at retard but it have not under high normal load. One of the notable features of annealing specimen is steady flanking initial time for a normal load in this experiment. Failure mechanism of SM55C is due to the fatigue wear such like flanking, pitting etc.. Flanking leads to abruptly fracture of worn surface. Fracture mechanism has a connection with normal load and polishing direction of specimens.

• Tribology and Lubricants
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• 제11권3호
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• pp.11-23
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• 1995

The friction and wear behavior of $Al_{2}O_{3}$, SiC, and $Si_{3}N_{4}$ under the different sliding conditions were investigated. The cylinder-on-disc wear tester was used for a wear test method. Using the servo-motor, the sliding speed did not alternate due to the frictional forces. Three kinds of loads were selected to watch the variation of the wear rates and the frictional forces under a constant speed. Three kinds of sliding conditions were used to see the effects of the oxidation and the abrasion. The dominant wear mechanisms of $Al_{2}O_{3}$ were the abrasion and the formation of transfer layers. The abrasion has a great effect on the wear of SiC. The wear of $Si_{3}N_{4}$ was due to the asperity-failure and the oxidation. Also, the wear rate of each ceramic is shown to be related to the frictional power provided to the tribological system.

• 한국공작기계학회논문집
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• 제11권5호
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• pp.30-37
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• 2002

Single flighted screw injection technology is the most cost effective method for the production of film, sheet, pipe and the fundamental step in other processes including blow molding and injection molding. The temperature of polymer melts and injection pressure play a very important role in the injection molding machine. Thermal distortion and displacement of a screw by temperature difference and injection pressure difference ratio cause a friction and thermoelastic wear by metal-to-metal contact between the screw and the cylinder. In this paper we analyzed thermal distortions of a screw as functions of temperature distribution and pressure profiles by finite element analysis.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.35-41
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• 1999

Friction and wear test was performed for nylon, acetal resin, and PTFE(polytetrafluoroethylene) under reciprocating dry sliding conditions against a steel counterpart. Friction coefficient and specific wear rate were analysed as a function of sliding distance and applied load. The worn surfaces of plate and disc specimens were observed using SEM(Scanning Electron Microscopy). The experimental results show that acetal resin exhibited lowest wear rates whereas PTFE possessed lowest friction coefficient. The prominent wear mechanisms found were adhesion and abrasion.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.218-221
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• 2004

Dry sliding wear behavior of electro-pressure sintered Co, $Co-20\;wt.\%$ CuSn and $Co-20\;wt.\%$ WC composites were investigated. Wear tests of the materials were carried out using a pin-on-disk wear tester at various loads of 10N-100N under a constant sliding speed condition of 0.38m/s against glass ($83\%\;SiO_2$) beads. Sliding distances were varied with a range of $100m{\sim}600m$. A scanning electron microscopy was used to examine morphologies of worn surfaces, cross-sections, and wear debris. The $Co-20\;wt.\%$ WC composite had the highest and the $Co-20\;wt.\%$ CuSn composite showed the lowest wear resistance among the tested materials. All specimens exhibited low friction coefficients ranging from 0.12 to 0.4 at the applied load of 100N.

• Tribology and Lubricants
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• 제16권3호
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• pp.166-172
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• 2000

The friction and wear characteristics of dental composite resins such as Charisma, Elitefil, TPH and Veridonfil were investigated. Furthermore, The surface characteristics examination, the analysis of contents of filler, Victors hardness and fracture toughness measurement of composite resins were preformed. The wear test applied ball to move reciprocationally on flat wear tester at room temperature. Microstructure of surfaces and worn surfaces were observed by SEM. Experimental results indicate that the friction coefficient of TPH was quite low, and the wear resistance of TPH was better than that of Charisma, Elitefil or Veridonfil at the same condition. The main wear mechanism was found to be plastic flow and abrasive wear by failure of filler's bond to the matrix.

• Tribology and Lubricants
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• 제20권3호
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• pp.125-131
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• 2004

Nano-wear behavior of amorphous carbon films was studied by Atomic Force Microscopy. The a-C films are deposited on Si(100) substrate by DC magnetron sputtering method. The influences of different surface roughness on the nano-wear are investigated. Nano-wear tests were carried out using a very sharp diamond coated tip. Its spring constant was 1.6 N/m and radius of curvature was 110 nm. Normal force used in the wear tests ranged 0 to 400 nN. It was found that surface depression occurred during scratching because of plastic deformation and abrasive wear (cutting St ploughing). Wear depth increased linearly with normal force. Changing the surface roughness variables according to the bias pulse control, the less surface roughness decreased the wear depth. The thickness did not affect the wear resistance.

• 한국재료학회지
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• 제15권4호
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• pp.224-232
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• 2005

Dry sliding wear behavior of electro-pressure sintered Fe-Ni and Co-Fe-Ni compacts was investigated. Pin-on-disk wear tests were performed on the sintered Fe-Ni, Co-Fe-Ni disk specimens against alumina $(Al_2O_3)$ and silica $(SiO_2)$ ball counterparts at various loads ranging from 3N to 12N. A constant sliding speed of 0.1m/sec was employed. Wear rate was calculated by dividing the weight loss measured after the test by specific gravity and sliding distance. Worn surfaces and cross sections of them were examined by a scanning electron microscopy, and wear mechanism of the compacts was investigated. Wear characteristics of the compacts were discussed as a function of composition of the compacts. Relationship between the wear rate and mechancial properties of the compact was explored, and effects of the oxide layer that was formed on wearing surface of the compacts on the wear were also studied.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.354-357
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• 2009

The effect of texture of an extruded OFHC Cu rod on its sliding wear has been explored. Disk specimens with three different orientations were machined from the Cu rod for the wear test; surfaces of the disk were perpendicular ($0^{\circ}$), inclined with a specific angle ($45^{\circ}$), and parallel ($90^{\circ}$) to the extrusion axis of the rod. The texture was analyzed using an X-ray goniometer by measuring {111}, {200}, and {220} pole figures of each specimen. The analyzed texture was correlated with wear-test results of the Cu specimen. Dry sliding wear tests were performed at room temperature using a pin-on-disk wear tester against an Al2O3 ball. Applied load, sliding distance, sliding speed were fixed as 20 N, 200 m, and 0.5 m/sec, respectively. The $45^{\circ}$-inclined (to the extrusion axis) disk specimen showed the lowest wear resistance with the least data scatters. It has been found that distribution of cube texture strongly influences wear rate of the extruded Cu rod.

• 대한기계학회논문집
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• 제16권7호
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• pp.1266-1277
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• 1992

본 연구에서는 공구의 형상과 절삭조건에 따른 공구의 결손형태를 예측하기 위하여 현재 가장 널리 쓰이고 있는 인볼류우트커터의 결손형태를 절삭날의 응력분포 값으로 예측하고 실험에 의하여 검증함과 동시에 기어 절삭실험을 통한 공구 결손의 성장거동을 고찰하였으며, 또한 마멸과 결손이 발생함에 따른 절삭력의 변화와 평형을 관찰하여 상호관련성을 비교함으로써 인볼류우트 기어커터의 초기 결손을 해석적으로 예측하였다.