• Title/Summary/Keyword: Extrusion Die

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A Three-Dimensional Finite Element Analysis of Hot Square Die Extrusion Considering the Effect of Die Bearing (금형 베어링 효과를 고려한 평금형 열간 압출의 3차원 유한요소해석)

  • 강연식;양동열
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1996.10a
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    • pp.185-191
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    • 1996
  • The Variation of die bearing is primary way to control the metal flow in hot square die extrusion process. Finite element computations are carried out to assess the influence of die bearing on metal flow and state variables. The finit element method is developed based on ALE description for a rigid-viscoplastic material. Since thermal state computational example, hot square die extrusion with varied die bearing lengths has been analyzed for the profile of a L-section.

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The Analytical Consideration for Several Design Parameters of Flat-Die Extrusion Processes (평금형 압출공정 설계 인자에 대한 해석적 고찰)

  • 이창희;양동열
    • Transactions of Materials Processing
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    • v.10 no.7
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    • pp.551-557
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    • 2001
  • In the present study, several design parameters of the flat-die extrusion process are investigated using the finite element method. The effects of the location of an extrusion profile, arrangement of multiple extrusion profiles, and the design of various die land have been investigated through the analysis. Several numerical examples of flat-die extrusion of such as C-section, multiple U-shape, and a window guide section, are analyzed. From the comparative study, the effect of design parameters is investigated. In each example, comparing the velocity distribution with that of the original design, it has been shown that the design modification affords more uniform distribution.

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Flow Analysis of Resin in an Extrusion Die for the Production of Medical Catheter Tubes (의료용 카테타 튜빙의 압출을 위한 다이내의 수지 흐름해석)

  • Lee, M.A.;Lyu, M.-Y.;Shin, D.J.;Kim, T.K.
    • Transactions of Materials Processing
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    • v.24 no.2
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    • pp.89-94
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    • 2015
  • Medical catheter tubes are disposable devices that are inserted into the body cavities such as the pleura, trachea, esophagus, stomach, urinary bladder, ureter, or blood vessels for surgical procedures. Each hole of the inner tube is called a lumen, which is used as a passage for drug injections, waste discharge, polypus removal, blood transport, or injection of a camera or sensor. The catheter tube is manufactured by extrusion. The flow in the inner extrusion die affects the thickness and diameter of the tube. In the current study computer simulation of flow in an extrusion die for catheter tubing was performed. Velocity, pressure, shear rate, and shear stress were investigated and the die design was examined.

The Effect of Porthole Shape on Elastic Deformation of Die and Process at Condenser Tube Extrusion (포트홀 형상이 컨덴서 튜브 직접 압출 공정 및 금형 탄성 변형에 미치는 영향)

  • Lee, J.M.;Kim, B.M.;Jo, H.;Jo, H.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.315-318
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    • 2003
  • Recently, condenser tube which is used for a cooling system of automobiles is mainly manufactured by the conform extrusion but this method is inferior as compared with direct extrusion in productivity per the unit time and in the equipment investment. Therefore, it is essential for the conversion of direct extrusion with porthole die. The direct extrusion with porthole die can produce condenser tube which has the competitive power in costs and qualities compared with the existing conform extrusion. This study is designed to evaluate metal flow, welding pressure, extrusion load tendency of mandrel deflection that is affected by variation of porthole shape in porthole die. Estimation is carried out using finite element method under the non-steady state. Also this study was examined into the cause of mandrel fracture through investigating elastic deformation of mandrel during the extrusion.

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Practical Determination of the Die Shape Using a Streamline in Axisymmetric Extrusion (유동경로를 이용한 축대칭 금형 형상의 실용적 ,결정)

  • 이용신
    • Transactions of Materials Processing
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    • v.10 no.2
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    • pp.111-114
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    • 2001
  • A new, simple method to determine the die shape using a streamline in extrusion is presented. This method assumes that a billet deforms naturally to minimize the energy input for the given process condition. Then, an optimal die shape can be determined along a streamline. Extrusion operations with two types of materials, strain-hardening material and strain-rate hardening material, are examined using this method. Predictions with the proposed method are compared with those by the previous optimizing model to show its efficiency.

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A Practical Method to Determine the Die Shape using a Streamline in Axisymmetric Extrusion (축대칭 압출에서의 유동경로를 이용한 실용적 금형설계)

  • 윤상헌
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.04a
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    • pp.79-82
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    • 2000
  • A new simple method to determined the die shape using a streamline in extrusion is presented. This method assumes that a billet deforms naturally to minimize the energy input for the given process condition. Then an optimal die shape can be determined along a streamline. Extrusion operations with two types of materials strain-hardening material and strain-rate hardening material are examined using this method. Prediction with the proposed method are compared with those by the previous optimizing model to show its efficiency.

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Phenomenological Analysis of the Effects of Die Cooling and Extrusion Speed on the Extrusion of 7075 alloy (금형 냉각과 압출 속도가 7075 합금 압출에 미치는 영향에 대한 현상학적 분석)

  • Seong, S.G.;Kang, H.J.;Lee, S.Y.
    • Journal of the Korean Society for Heat Treatment
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    • v.34 no.4
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    • pp.185-190
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    • 2021
  • The extrusion experiments using the 7075 aluminum billet have been performed to investigate the effects of die cooling and ram speed on the occurrence of surface defects on the extrudate. The purpose of die cooling was to suppress overheating of the extrudate at the moment of extrusion. In the present die cooling system, liquid nitrogen has been injected in to the die and sprayed to the surface of extrudate. Ram speed was either kept or varied in the range of 1.1~1.7 mm/sec. throughout one extrusion shot to check the occurrence of surface defects. Every extrusion started at a ram speed of 1.25 mm/sec. The temperature of extrudate was measured using a laser thermometer. The 7075 billet of 180 mm in diameter and 550 mm in length was preheated at 390℃ and extruded to get a single plate of 8000 mm in length, 150 mm in width and 10 mm in thickness. Each extrudate was checked by eye to find the surface defects. The microstructures were obtained in the specimen cut from each corner of the extrudate using the EBSD micrographs.

The Effect of Die Cooling on the Surface Defects of the Aluminum 7075 Extrudates (알루미늄 7075 합금의 압출에서 금형 냉각이 압출재의 표면 결함에 미치는 영향)

  • S.Y., Lee
    • Journal of the Korean Society for Heat Treatment
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    • v.35 no.6
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    • pp.319-326
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    • 2022
  • Direct extrusions of an aluminum 7075 alloy were carried out using 1500 ton machine with and without die cooling system. Cooling of extrusion die has been performed by the flow of liquid nitrogen and controlled by laser thermometer. Billet was 180 mm in diameter and 500 mm in length. The preheating temperatures of billet, container and die were 390℃, 400℃ and 450℃, respectively. Ram speed was kept with 1.25 mm/sec first. The change of ram speed was carried out during extrusion according to the observation of surface defects such as crack or tearing. Extrudates of 8.3 m in length, 100 mm in width and 15 mm in thickness were obtained to observe and analyze surface defects by optical microscopy and EBSD (Electron BackScattered Diffraction). In case of extrusion without die cooling cracks on the surface and tearing in the corner of extrudate occurred in the middle stage and developed in size and frequency during the late stage of extrusion. At the extrusion with die cooling the occurrence of defects could be suppressed on the most part of extrudate. EBSD micrographs showed that cracks and tearings have been resulted from the same origin. Surface defects were generated at the boundaries of grains formed by secondary recrystallization due to surface overheating during extrusion.

Investigation into Effect of the Shape of Lip Die on Flow Characteristic in the Extrusion of Plate Wider than the Diameter of the Round Billet Using Lip Die (립(Lip) 금형을 이용한 원형 빌렛 직경 이상의 판재 압출에서 금형 형상이 금속 유동에 미치는 영향에 대한 연구)

  • 김경진;이창희;양동열
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.265-268
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    • 2003
  • In the extrusion process, the working material is forced to flow through a die with the desired profile. In general, the width of an extruded section is limited to about an inch less than the diameter of the round billet. But through the lip die, material is spreaded to produce a wider extruded section than the diameter of round billet. In this study, the extrusion process of an aluminum plate using the lip die is investigated. The width of the extruded plate is 450mm that is formed from the round billet with a diameter of 250mm. The flow characteristic through the lip die is considered to produce the wide-extruded plate with a small billet using rigid plastic FE analysis. Based on the result of FE analysis, new designs of lip die are proposed.

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A Study on the Optimal die angle of the Torsional Forward Extrusion Process (비틀림 전방압출 공정의 최적다이각에 관한 연구)

  • Lee S. I.;Kim Y. H.;Ma Xiang
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.11a
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    • pp.23-32
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    • 2002
  • The torsional forward extrusion is the process that is executed by punch travel and die rotation. The advantages of having the die rotation on this process are that forming load can be reduced and optimal die angle can be increased. This provides a possibility to extrude cold-worded material where a large extrusion force and die angle are required. Also, this process can improve the material properties owing to the high deformation and uniform strain distribution. The forming load and optimal die angle of this process are determined by the upper bound analysis using stream function and the optimization technique. To verify the theoretical result, we have carried out experiments and FE simulations using DEFORM3D.

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