• 제목/요약/키워드: Microcutting

검색결과 13건 처리시간 0.022초

분자동역학을 이용한 공구형상에 따른 미소절삭현상에 관한 연구 (A Study on the Microcutting for Configuration of Tools using Molecular Dynamics)

  • 문찬홍;김정두
    • 한국정밀공학회지
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    • 제12권4호
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    • pp.135-142
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    • 1995
  • Recently, the analysis of microcutting with submicrometer depth of cut is tried to get a more high quality surface product, but to get a valuable result another method instead of conventional finite element method must be considered because finite element method is impossible for a very small focused region and mesh size. As the alternative method, Molecular Dynamics or Statics is suggested and accepted in the field of microcutting, indentation and crack propagation. In this paper using Molecular Dynamics simulation, the phenomena of microcutting with subnanometer chip thickness is studied and the cutting mechanism for tool edge configuration is evaluated. As the result of simulation the atomistic chip formation is achieved.

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분자동력학을 이용한 공구형상에 따른 미소절삭현상에 관한 연구 (A Study on the Microcutting for Configuration of Tools using Molecular Dynamics)

  • 뮨찬홍;김정두
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1993년도 추계학술대회 논문집
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    • pp.83-88
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    • 1993
  • Recently, the analysis of microcutting with submicrometer depth of cut is tried to get a more high quality surface product, but to get a valuable result another method instead of conventional finite element method must be considered because finite elment method is impossible for a very small focused region and mesh size. As the altermative method, Molecular Dynamics or Statics is suggested and acceoted in the field of microcutting, indentation and crack propagation. In this paper using Molecuar Dynamics simulation, the phenomena of microcutting with subnanometer chip thickness is studied and the cutting mechanism for tool edge configuration is evaluated. As the result of simulation the atomistic chip formation is achieved.

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연마제 워터젯을 이용한 복합재 미세가공의 백화현상에 대한 연구 (A Study on the Frosting Phenomena of Abrasive Waterjet Microcutting for Multi-Layered Materials)

  • 박강수;박연경;고정상;신보성
    • 한국공작기계학회논문집
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    • 제16권5호
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    • pp.183-190
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    • 2007
  • It is well known that abrasive waterjet(AWJ) was developed as a kind of high-density energy processing technologies. AWJ is used to obtain the better cutting quality of various materials such as metals, ceramics, glass and composite materials within a short manufacturing time because of the characteristics of heatless and noncontact processing. However, AWJ device still has some problems to obtain the high quality of thin workpiece. In this paper, we investigated the optimal microcutting conditions of AWJ, such as maximum pressure, cutting speed and standoff distance of thin multi-layered materials. The experimental results show that AWJ has possibilities and potential to apply to the microcutting of thin multi-layered materials for IT industrial applications.

Rapid Propagation of Pelagonium Inquinans Via Organogenesis from Mature Leaf Explants

  • Hwang, Sung-Jin
    • 한국약용작물학회지
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    • 제14권2호
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    • pp.92-95
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    • 2006
  • A method for plant regeneration via organogenesis from Pelagonium inquinans leaf disc has been developed. Mature leaf explants were collected from field-grown plants and used for the induction of adventitious shoot regeneration on Murashige and Skoog (MS) medium supplemented with 3% (w/v) sucrose plus plant growth regulators. Maximum shoot organogenesis, with $11.8{\pm}1.5$ shoots (98.6%) per leaf disc, was obtained with $2\;mg/l$ $N^6-benzyladenine$ (BA) and $0.5\;mg/l$ ${\alpha}-naphthyleneacetic$ acid (NAA) in 30 days. For rooting, the in vitro proliferated and elongated shoots were excised into 1.5-2 cm in length microcutting, which were plated individually on an half-strength MS (1/2MS) medium supplemented with 2% (w/v) sucrose plus various concentrations of indole-3-butyric acid (IBA). Shoots rooted with a frequency of 100% following culture on 1/2MS medium containing $0.5\;mg/l$ IBA.

단결정 다이아몬드 공구를 이용한 미세 패턴 가공성에 대한 실험적 분석 (Experimental Investigation on Machining Feasibility of Micro Patterns using a Single Crystal Diamond Tool)

  • 김현철
    • 한국기계가공학회지
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    • 제11권5호
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    • pp.76-81
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    • 2012
  • The continuing demand for increasingly slimmer and brighter liquid crystal display(LCD) panels has led to an increased focus on the role of the light guide panels(LGPs) or optical films that are used to obtain diffuse, uniform light from the backlight unit(BLU). And the most basic process in the production of such BLU components is the micromachining. LCD BLUs comprise various optical elements such as a LGP, diffuser sheet, prism sheet, and protector sheet with micro patterns. High aspect ratio patterns are required to reduce the number of sheets and enhance light efficiency, but there is a limit to the aspect ratio achievable for a given material and cutting tool. Therefore, this study comprised a series of experimental evaluations conducted to determine the machining feasibility in microcutting various aspect ratio patterns on electroless nickel plated die materials when using single-crystal diamond tools. Cutting performance was evaluated at various cutting speeds and depths of cut using different machining methods and machine tools.

SEM 내 마이크로 절삭에 의한 초경합금재의 절삭 특성에 관한 연구 (Study on Cutting Characteristics of WC-Co with Micro Cutting in SEM)

  • 허성중
    • 한국정밀공학회지
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    • 제20권10호
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    • pp.74-81
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    • 2003
  • This paper describes that the micro-cutting of WC-Co using PCD (Polycrystalline Diamond) and PcBN (Polycrystalline Cubic Boron Nitride) cutting tools are performed with SEM(Scanning Electron Microscope) direct observation method. The purpose of this study is to present reasonable cutting conditions to obtain precise finished surface and machining efficiency. Summary of the results are shown below: (1) The thrust cutting forces tend to increase more than the principal forces as the depth of cut and the cuttlllg speed are increased preferably on orthogonal microcutting. (2) The tool wear in the flank face was formed larger than that in the rake face on orthogonal micro cutting. (3) The wear appearance for PCD tools is abraded by hard WC particles of the work materials, which lead diamond grain to be detached from the bond.

탄소 섬유 강화 고분자 복합재의 연삭마모 특성에 관한 연구 (Study on Abrasive Wear Behaviour of a Carbon Fiber Composites)

  • 고성위;양병춘;김형진;김재동
    • 동력기계공학회지
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    • 제10권1호
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    • pp.46-51
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    • 2006
  • Present study was investigated the effect of the particle of the counterface of unidirectional carbon fiber reinforced composite. The friction coefficient of composite and the specific wear rate different sliding velocity were measured for this materials. The friction track of counterface was observed by an optical microscope and scanning electron microscope. There were insignificant effects of the specific wear rate under lower Sic abrasive particle, however it showed high effect on $30{\mu}m$ abrasive particle size. There were significant effects of friction and wear behavior of the fiber direction under 0.3m/s sliding speed. Major failure mechanisms can be classified such as microfracture, plowing, microcutting, cutting and cracking.

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Flyash에 의한 STS304 재료의 내침식성 평가 (Evaluation on erosion resistance of STS304 by flyash)

  • 박해웅;이의열
    • 한국표면공학회지
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    • 제34권6호
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    • pp.575-584
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    • 2001
  • Erosion due to abrasive particles contained in gas streams from boilers has been emerged as a significant problem in the coal fired power plants. Particle erosion accounted for approximately 50% of boiler failures and especially flyash erosion was responsible for 20~30% of emergency boiler shutdowns. Particularly, because of the high ash loading and high velocity, most erosion occurs in the boiler tubes and economiser tube bank where the direction of the gas stream changes to $180^{\circ}$ .In this study, a high temperature particle erosion tester was used to evaluate erosion rate in a simulated environment. The erosion parameters such as erosion temperature, particle impact angle, particle velocity and various particle size were changed. Flyash is the combustion product of the pulverized coal, where size is ranging from 1 to $200\mu\textrm{m}$. Flyash composed of mainly SiO$_2$, $A1_2$$_O3$, and $Fe_2$$O_3$has dense spherical particles and irregular particles containing numerous pores and cavities. From the erosion tests at various conditions, the maximum erosion was experienced at impact angles of $30^{\circ}$ to $60^{\circ}$ In addition, erosion rate increased in proportional to velocity and temperature. And from the observation of the eroded surfaces, it was also concluded that 304 stainless steel was mainly eroded by extrusion-forging at high impact angle ($90^{\circ}$) and by microcutting mechanism at low impact angles ($30^{\circ}$ and $45^{\circ}$).

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FRP 선박 외판재의 연삭마모 특성에 관한 상대재 거칠기의 영향 (Effect of Counterpart Roughness on Abrasive Wear Characteristics of Side Plate of FRP Ship)

  • 김형진;고성위;김재동
    • 한국해양공학회지
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    • 제22권6호
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    • pp.35-40
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    • 2008
  • The effect of counterpart roughness on abrasive wear characteristics of side plate materials of FRP ship, which were composed of glass fiber and unsaturated polyester resin composites, were investigated at ambient temperature by pin-an-disc friction test. The friction coefficient, wear rate and cumulative wear volume of these materials against SiC abrasive paper were determined experimentally. The wear rate of these materials decreased rapidly with sliding distance and then maintained a constant value. It was increased as counterpart roughness was rougher in a wear test. The cumulative wear volume tended to increase nonlinearly with sliding distance and depended on applied load and sliding speed for these composites. It could be verified by SEM photograph of fracture surface that major failure mechanisms were overlapping layers, microcutting, deformation of resin, delamination, and cracking.