• Title, Summary, Keyword: extrusion

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Analysis of microstructure and texture evolution in AZ31Mg alloy fabricated by direct/indirect extrusion process (직/간접 압출공정에 의해 제조된 AZ31Mg 합금의 미세조직 및 집합조직 변화 분석)

  • Kim, D.H.;You, B.S.;Park, S.S.;Yoon, D.J.;Choi, S.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.38-41
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    • 2008
  • To investigate the evolution of microstructure and texture in AZ31 Mg alloy, direct/indirect extrusion process was carried out at $300^{\circ}C$ with various extrusion speeds. The distribution of grain size depends on extrusion method and extrusion speed. More homogeneous grain site can be obtained at higher extrusion speed of indirect extrusion process. Extrusion speed does not affect significantly texture evolution during extrusion process regardless of extrusion method. ODF section is more useful to understand texture evolution during extrusion process compared with pole figure.

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Effect of Extrusion Conditions on Microstructures and Mechanical Properties of AM80 Magnesium Alloys (AM80 마그네슘 합금의 미세조직 및 기계적 특성에 대한 압출조건의 영향)

  • Lee, S.K.;Kim, D.H.;Kim, D.H.;Lim, S.G.
    • Transactions of Materials Processing
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    • v.27 no.6
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    • pp.379-385
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    • 2018
  • This study investigated the effect of extrusion conditions on microstructures and mechanical properties of AM80 magnesium alloys. The billets of magnesium alloy used for hot extrusion were prepared by permanent mold casting method, and its extrusion was hot direct extrusion with different extrusion conditions. The results of microstructural analysis showed that the main phases in the as-casted alloys were ${\alpha}-Mg$, ${\beta}-Mg_{17}Al_{12}$, and lamella $Mg_{17}Al_{12}$. Hot extrusion results, The tensile strength of the most soundly manufactured extruded bars (extrusion temp: $350^{\circ}C$, extrusion ratio: 27:1, ram speed: 2mm/s) was approximately 327MPa at room temperature. The increase in the mechanical properties of hot-extruded alloys was as a result of grain refinement by dynamical recrystallization during hot extrusion.

Effect of the Design Parameter for Internal Spline Forming Using the Tube (중공축 내접 스플라인 성형을 위한 설계변수의 영향)

  • Wang, C.B.;Lim, S.J.;Park, Y.B.
    • Transactions of Materials Processing
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    • v.15 no.7
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    • pp.512-517
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    • 2006
  • In this paper, the cold extrusion process for internal spline forming using a thin and long tube has been analyzed by using a rigid plastic finite element code. The internal spline consists of 10 tooths. The cold extrusion process has been focused on the comparisions of load-stroke relation and filling states of the teeth according to design parameters. The design parameters involve extrusion ratio, extrusion angle and friction factor. The internal spline forming can cause the buckling and folding during the cold extrusion process because of using a thin and long tube. The optimum design parameters have been obtained through rigid-plastic finite elements analysis. The extrusion ratio and extrusion angle have great effects on the deformation characteristics of the cold extrusion process.

Thixo-extrusion of Semi Solid 7075 Aluminum Alloys and Mechanical Properties of The Extrudates (반응고 7075 알루미늄 합금의 반용융 압출 및 압출재의 기계적 특성)

  • Choi, Tae-Young;Kim, Dae-Hwan;Kim, Soo-Bae;Shim, Sung-Young;Lim, Su-Gun
    • Journal of Korea Foundry Society
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    • v.34 no.3
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    • pp.87-93
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    • 2014
  • Thixo-extrusion of semi-solid 7075 aluminum alloy and the mechanical properties of its extrudates were investigated. The semisolid alloy was prepared by a cooling slope cast. In other to perform thixo-extrusion, semi-solid 7075 aluminum alloy billets were reheated at the reheating conditions reported in a previous study. The maximum extrusion pressure in thixo-extrusion was 615MPa. This was lower than that of conventional hot extrusion ($P_{max}=940MPa$) at the same extrusion conditions due to the increased fluidity of the alloy billet in the semi-solid state. The values of Rockwell hardness (scale B) at the extrusion direction of the as thixoextruded bar were 48~53HRB and the difference in Rockwell hardness between the transverse direction and the extrusion direction was 5HRB or less. The results show that thxio-extrusion of semi-solid 7075 Al alloy improves the workability and anisotropic with the extrusion direction compared with hot extrusion of the conventional alloy.

Extrusion Die Development of Interior & Exterior Parts for High Speed Train on Aluminum Alloys and Controls of Extrusion Conditions (고속전철 내·외장재용 알루미늄 합금의 압출 금형 개발 및 압출 조건의 제어)

  • Kim, Kee Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.50-55
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    • 2018
  • The important thing in extrusion technology is the design and production of molds. Appropriate design of the molds is essential for achieving the desired extrusion of molds at the same time to maximize the life of the molds and increase their efficiency. The extrusion temperature and extrusion speed are the main parameters at the time of extrusion. Different extrusion conditions should be added depending on the extrusion ratio, physical properties of the material, and type of extrusion. In this study, the extrusion process of various 6xxx series aluminum cast alloys for high speed train interior or exterior parts were investigated. The extruded die design was performed for the 6063, 6061, 6N01, 6005, 5083 and 6060 alloy profiles and an extrusion test was conducted. In addition, the extrusion conditions, such as extrusion pressure following as the billet temperature, extrusion temperature, and materials change, were analyzed. Although the 6063 aluminum alloy can be extruded at the lowest temperature and pressure, the 6061 alloy can be extruded at the highest temperature and pressure. From these results, the successful extruded products were manufactured from these established conditions.

The Characteristics of Hot Hydrostatic Extrusion of AZ Magnesium Alloy (AZ계 마그네슘 합금의 열간 정수압 압출특성 연구)

  • Yoon, D.J.;You, B.S.;Lim, S.J.;Kim, E.Z.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.62-65
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    • 2008
  • Extrusion characteristics of Mg alloys were studied experimentally. The Al-Zn-Mg alloys, AZ31, AZ6l, AZ80, and AZ91 were extruded with hot hydrostatic extrusion process. The hydrostatic process was efficient to reduce surface friction and extend steady state region in extrusion which made it more convenient to examine deformation behavior of the alloys avoiding the disturbance caused by temporary contact state between billet and die, and billet and container. High pressure was cooperative to expand forming limit of the alloys which were applied on the billet during the extrusion process. Extrusion limits were traced in temperature and extrusion speed domain with changing composition of the alloying elements. Effects of process parameters on extrusion load and microstructure evolution were investigated also.

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The Effect of Process Parameter in Direct Extrusion of Copper Clad Aluminum Composite Materials (Cu-Al 층상 복합재료의 직접압출시 공정변수의 영향)

  • 윤여권;김희남;김용수
    • Journal of the Korean Society of Safety
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    • v.15 no.4
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    • pp.28-34
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    • 2000
  • Copper clad aluminum composite materials are being used for economic and structural purposes, The development of an efficient production method of copper clad aluminum composite material rods by extrusion is very important. This paper describes experimental investigations in the direct extrusion of copper clad aluminum rods through conical dies. There are several parameters that have an influence on determining a sound clad extrusion. These variables are extrusion temperature, extrusion ratio, semi-cone angle of die, extrusion force, extrusion velocity, friction of between the container and billet, percentage of copper used and ratio of flow stress of copper to aluminum. In order to investigate the influence of extrusion temperature, extrusion ratio, semi-cone angle of die on the hot direct extrudability of the copper clad aluminum composite material rods, the experimental study have been performed with these variation.

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Unsteady State Analysis of Al Tube Hot Extrusion by A Porthole Die (포트홀 다이에 의한 Al 튜브의 비정상상태 열간 압출 공정 해석)

  • 조형호;이상곤;박종남;김병민
    • Transactions of Materials Processing
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    • v.10 no.4
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    • pp.311-318
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    • 2001
  • Porthole die extrusion has a great advantage in the forming of long hollow section tubes. It is difficult to produce long hollow section tubes with complicated section by the conventional extrusion process with a mandrel on the stem Because of the limit of the length of mandrel and the complexity of cross section. Porthole die extrusion is affected by many parameters, such as extrusion ratio, extrusion speed, die geometry, porthole number, bearing length etc. Up to now, most of studies about porthole die extrusion have been investigated by experiments or steady state FE-analysis. However, in this paper, porthole die extrusion is analysed by the unsteady state 3D FE-simulation. And the result of unsteady state analysis is compared with the experimental result. Also, the surface state of extruded tubes are examined for the various process conditions.

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Development of Thixoextrusion Process for Light Alloys - Part 2. Thixoextrusion Process for Light Alloys (경량합금 반용융 압출 기술 개발 - Park 2. 반용융 압출 공정 기술)

  • Kim, Shae-K.;Yoon, Young-Ok;Jang, Dong-In;Jo, Hyung-Ho
    • Journal of Korea Foundry Society
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    • v.26 no.5
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    • pp.217-221
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    • 2006
  • The main emphasis of this study was to utilize thixoextrusion process for improving extrudability of 7075, 7003 Al wrought alloys and AZ31 Mg wrought alloy. The results of thixbextrusion experiments about microstructures and extrusion pressures were compared with conventional hot extrusion results. The maximum extrusion pressure of thixoextrusion was greatly decreased compared with that of conventional hot extrusion. It was pointed out that the extrusion temperature dependence of the maximum extrusion pressure was large and the influence of extrusion temperature on the improvement of extrudability was remarkable in thixoextrusion. This will contribute to extrudability in terms of extrusion pressure, which in turn means that shorter process time is required and smaller extrusion machine can be applied for the same operation. The elongated grains to extrusion direction were generally observed during conventional hot extrusion, while the thixoextruded microstructures were isotropic.