• Title/Summary/Keyword: 평금형 압출

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A Visioplasticity Analysis for Axisymmetric Extrusion through Square Dies Using Model Material (모델재를 이용한 축대칭 평금형 압출공정의 변형가시화 해석)

  • 한철호;엄태복
    • Transactions of Materials Processing
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    • v.5 no.2
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    • pp.156-164
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    • 1996
  • To investigate the behavior of plastic deformation in axisymmetric extrusion through square dies, experimental works with the plasticine as a model material are carried out at the room temperature. Some mechanical properties of the model material are determined by compression and ring compression tests. Visioplasticity method using expermental grid distortion in extrusion is introduced to analyze the plastic flow strain rate and strain distribution. In spite of severe deformation during the extrusion through square die the visioplasticity method shows good results for the distribution of effective strain rate and effective strain.

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An Upper-Bound Analysis of the Square-Die Forward Extrusion of Regular Polygonal-Shaped Tubes from hollow-Cylindrical Billets at Final Stage (중공 원형 소재로부터 다각형 튜브 제품의 평금형 전방 압출에 대한 최종단계의 상계해석)

  • Kim, Dong Kwon;Cho, Jong Rae;Bae, Won Byong
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.11
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    • pp.91-97
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    • 1995
  • In this study, a deformation model for the regular polygonal-shaped tubes from hollow-cylindrical billets is proposed and a kinematically admissible velocity field is obtained from this deformation model. The final stage upper-bound extrusion load and the average extruded length are determined by minimizing the total power consumption with respect to chosen parameters. Experiments have been carried out with hard solder billets at room temperature. The theoretical predictions of the extrusion load are in good agreements with the experimental results and there is generally reasonable agreement in average extruded height between theory and experiment.

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A study on the manufacture of extrusion square dies (평금형 CNC 가공 S/W 개발에 관한 연구)

  • 조승래
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.280-283
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    • 1999
  • Square dies are widely used for hot extrusion processes with high production rate. However the design and manufacture of square dies mainly relies on experience of industrial engineers To overcome such difficulty this study develops a method of automatic generation of NC-codes for the manufacture of extrusion square dies. The result shows that the method can reduce the lead time for the design and manufacture of square dies as well as eliminating engineers ow experience.

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Experimental Investigation on the Flow Control in Non-Axisymmetric Flat Die Extrusion-1 (비축대칭 평금형 압출에서 유동제어에 관한 실험적 연구-I)

  • Bae, W.B.;Kim, Y.H.;Park, J.W.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.12
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    • pp.136-141
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    • 1996
  • In this paper, the design variables of the extruded parts involving flat die through model experiment are investigated to overcome some current problems such as bending and twisting and get more improved quality products. Above all, the deformation behavior is analyzed in experiment and investigated flow charactristics inside container. Finally, the straight extruded product is obtained by modified bearing land width on the basis of the exit velocities distribution from bended and twisted products.

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Three-dimensional finite element analysis of hot square die extrusion by using split ALE method (분할된 ALE 방법에 의한 평금형 열간압출의 3차원 유한요소해석)

  • Kang, Yeon-Sick;Yang, Dong-Yol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.11
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    • pp.1912-1920
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    • 1997
  • In the analysis of metal forming process, ALE(Arbitrary Lagrangian Eulerian) finite element methods have been increasingly used for the capability to control mesh independently from material flow. The methods can be divided into two groups i.e., coupled and split formulations. In the present work, the split ALE formulation is used for computational efficiency. A split ALE finite element method developed for rigid-viscoplastic materials and applied to the analysis of hot square die extrusion. Since thermal state greatly affects the product quality, an ALE scheme for temperature analysis is also presented. As computational examples, profile shapes as square and cross-like sections are chosen.

Experimental investigation on the flow control in non-axisym- metric flat die extrusion-II (비축대칭 평금형 압출에서 유동제어에 관한 실험적 연구-II)

  • 김영호;배원병;강범수;박재우
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.3
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    • pp.130-136
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    • 1997
  • The velocity distrubution at the exit of extrusion die depends on the width of bearing land very much. When uniform bearing land without flow guide is used, the material which is extended through the same die does not, deflect to the constant direction, but when the flow guide is equipped and then the volume compensation is done accurately, the material deflects to one constant direction. Therfore, the part of problem can be known exactly, and extrusion products of straight shape can be produced by the corrected bearing land width.

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A Three-Dimensional Rigid-Viscoplastic Finite Element Analysis of isothermal Square Die Extrusion of a Square Section Based on ALE Description (강-점소성 ALE 유한요소 수식화에 근거한 사각형 형재의 평금형 등온 압출에 대한 3차원 해석)

  • 강연식;양동열
    • Transactions of Materials Processing
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    • v.5 no.1
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    • pp.55-60
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    • 1996
  • In the finite element analysis of metal forming processes the updated Lagrangian approach has been widely and effectively used to simulate the non-steady state problems. however some difficulties have arisen from abrupt flow change as in extrusion through square dies. In the present work an ALE(arbitrary Lagrangian-Euleria) finite element formulation for deforma-tion analysis are presented fro rigid-viscoplastic materials. The developed finite element program is applied to the isothermal analysis of square die extrusion of a square section. The computational results are compared with those by the updated Lagrangian finite element analysis.

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Investigation of the Final-Stage Forward Extrusion of Regular Polygonal-Shaped Bars From Circular Billets Using Square Die (평금형을 이용한 원형 소재에서 다각형바의 최종단계 전방압출에 관한 연구)

  • 김동권;조종래;배원병
    • Transactions of Materials Processing
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    • v.4 no.1
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    • pp.59-69
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    • 1995
  • A simple kinematically admissible velocity field is proposed to determine the final-stage extrusion load and the average extruded length in the square-die forward extrusion of regular polygonal-shaped bars from circular billets. From the proposed velocity field, the upper-bound extrusion load and the average extruded length are determined by minimizing the total power consumption with respect to four parameters. Experiments have been carried out with hard solder billets at room temperature. The theoretical predictions of the extrusion load are in good agreements with the experimental results and there is generally reason able agreement in average extruded length between theory and experiment.

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An Axisymmetric Finite Element Analysis of Hot Tube Extrusion Using Ceramic Dies (세라믹 금형을 이용한 열간 튜브 압출의 축대칭 유한요소해석)

  • Kang, Yeon-Sick;Yang, Dong-Yol;Chung, Soon-Kil;Lee, June-Gunn
    • Transactions of Materials Processing
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    • v.7 no.1
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    • pp.72-80
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    • 1998
  • This study is concerned with the thermo-biscoplastic finite element analysis of hot tube extrusion through square dies with a mandrel. The problem is treated as a non-steady state and the ALE description is used due to abruptly turning flow at the die aperture. Since the contact heat transfer coefficient and the friction factor are required in the analysis experiments are also carried out to determine the values, In order to apply ceramics to an extrusion die the study is focussed on under-standing the characteristics of the process. The simulated results provide the useful informations such as metal flow temperature distribution stress state etc. The elastic analysis of the dies is carried out to obtain the stress state of the ceramic dies.

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A Study on the Automatic Design of Dies for Hot Extrusion of Aluminium Alloys (알루미늄 합금 형재의 열간압출 금형 설계 자동화에 관한 연구)

  • 이춘만;송인성;정원지
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.1
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    • pp.135-143
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    • 2003
  • This study presents development of a automatic design software for process and die design of hot extrusion of aluminium alloys through square dies. The design of extrusion dies is still an art rather than a science with increasing complexity of shape and thinness of section. Therefore, most of the die design is still dependent on personal judgement, intuition and experience. The objective of this study is to develop a software system which includes a design rule extracted from literatures and experts in the extrusion industry. The developed system is effectively used to design extrusion processes and dies with reduced lead time and trial extrusion.