• 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.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.10a
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• pp.64-73
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• 1994

An updated Lagrangian finite element analysis with automatic remeshing scheme is applied to the three-dimensional hot extrusion through landless square dies. In the remeshing procedure, it is very difficult that the meshes are generated automatically with consideration of physical characteristics. In the presented study, the mesh generation is accomplished by modular concept. The generated meshes by modular concept have advantages, especially for three-dimensional problems, such as economized computational time and consideration of physical characteristic. In the problem, orifice shapes of square die are divided into two for the extrusion of solid sections. The orifice adaptive modules are developed for each type and the numerical examples are carried out for each type.

• Transactions of Materials Processing
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• v.7 no.4
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• pp.364-374
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• 1998

It is the objective of this study to analyze the effect of various process variables on the quality of extruded product and extrusion force for semi-solid extrusion of Al2024 with solid phase structure of globular type by the finite element method. Process variables are initial solid fraction, ram speed, semi-angle of die, and reduction in area. The results of experiment are compared with those of simulation in order to verify the usefulness of the developed finite element program. The flow and deformation of semi-solid alloy are analyzed by coupling by coupling the deformation of porous skeleton and the flow of liquid phase. It is also assumed that initial solid fraction is homogeneous.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.2005-2015
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• 1994

An analytical method based on the upper bound approach for the cup-bar axisymmetric combined extrusion is presented to determine the deformation zones as well as extrusion load and deformed geometry in the early stage. A new kiematically admissible velocity field is derived by the appropriate transformation of the original velocity field and applying the flow function approach. The derived velocity field is directly related to the boundary function for the plastically deforming zones and the parameter controlling the flow direction to the forward part or backward part. Experiments are carred out with the annealed aluminum 2024 at room temperature for the various area reductions. The workhardening effect is considered in the formulation as a function of the height ratio between the deformed billet and the orighinal billet to calculate the extrusion pressures. The theoretical predictions for the extrusion loads and deformed configuration are in good agreement with the experimental results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.1010-1015
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• 2008

In this study, the characteristics of aluminum tube hydroformed products at different extrusion type and heat treatment conditions were investigated. For the investigation, as-extruded, full annealed and T6-treated Al 6061 tubes at different extrusion type were prepared. To evaluate the hydroformability, free bulge test was performed at room temperature to $300^{\circ}C$. Also mechanical properties of hydroformed products at various pre- and post-heat treatments were estimated by hexagonal prototype hydroforming test at $250^{\circ}C$. And the tensile test specimens were obtained from hexagonal prototype hydroformed tube. As a results, hydroformability of full annealed tube is $5{\sim}8%$ higher than that of extruded and T6-treated tube. The tensile strength and elongation of T6-post heat treated indirect extrusion tube were more than 330MPa and 12%, respectively. However, T6 pre treated hydroformed product represents high strength, 330MPa and low elongation, 8%. Therefore, Hydroformability of Al6061 tube showed similar value for both extrusion types. However flow stress of direct tube showed $20{\sim}50MPa$ lower value than indirect tube.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.254-257
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• 2007

In this study, hydroformability and mechanical properties of pre- and post- heat treated Al6061 tubes at different extrusion type were investigated. For the investigation, as-extruded, full annealed and T6-treated Al 6061 tubes at different extrusion type were prepared. To evaluate the hydroformability, uni-axial tensile test and free bulge test were performed at room temperature and $200^{\circ}C$. Also mechanical properties of hydroformed part at various pre- and post-heat treatments were estimated by tensile test. And the tensile test specimens were obtained from hexagonal prototype hydroformed tube at $200^{\circ}C$. As for the heat treatment, hydroformability of full annealed tube is 25% higher than that of extruded tube. The tensile strength and elongation were more than 330MPa and 12%, respectively, when hydroformed part was post-T6 treated after hydroforming of pre- full annealed tube. However, hydroformed part using T6 pre treated tube represents high strength and low elongation, 8%. Therefore, the T6 treatment after hydroforming for as-extruded tube is cost-effective. Hydroformability of Al6061 tube showed similar value for both extrusion types. But flow stress of seam tube showed $20{\sim}50MPa$ lower value.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.87-94
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• 1999

The automated die design program is developed for cold forging of axisymmetric parts which are mainly produced by forward extrusion, backward extrusion, composite extrusion and upsetting. For this study, firstly classification of forged parts and investigation of die construction type usually employed in forging industry are carried out and the most proper type from several kinds of die construction is proposed as a standardized one. Based on the die design rules summarized in the references such as handbooks, technical papers, monthly journals, etc. the automated die design program was made using AutoLISP language available in AutoCAD software of personal computer. This program interactively runs for only input data, for example, forging process, shape of forged parts, type of punch, split of die insert and design of shrinkage rings and then displays details of drawings necessary to make a forging die. When a variety of forging processes and forged parts are tested to examine the validity of this program, it was confirmed to give good results applicable to the forging die design in press shop.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.132-135
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• 2007

In this study, hydroformability and mechanical properties of pre- and post- heat treated Al6061 tubes at different extrusion type were investigated. For the investigation, as-extruded, full annealed and T6-treated Al6061 tubes at different extrusion type were prepared. To evaluate the hydroformability, uni-axial tensile test and free bulge test were performed at room temperature and $250^{\circ}C$. Also mechanical properties of hydroformed part at various pre- and post-heat treatments were estimated by tensile test. And the tensile test specimens were obtained from hexagonal prototype hydroformed tube at $250^{\circ}C$. As for the heat treatment, hydroformability of full annealed tube is 25% higher than that of extruded tube. The tensile strength and elongation were more than 330MPa and 12%, respectively, when hydroformed part was post-T6 treated after hydroforming of pre- full annealed tube. However, hydroformed part using T6 pre treated tube represents high strength and low elongation, 8%. Therefore, the T6 treatment after hydroforming for as-extruded tube is cost-effective. Hydroformability of Al6061 tube showed similar value for both extrusion types. But flow stress of seam tube showed $20{\sim}50MPa$ lower value.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.97-101
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• 2001

Fine metal (Au, Ag, Cu) wire was extruded with hydrostatic extrusion process in cold condition. A vertical type 900kN hydrostatic extruder has been developed. The extruder was facilitated with high pressure container which are available for hot and cold forming. The container endured 1400MPa internal pressure and extrusion ratio To was achieved in cold forming for Au fine wire which had $600{\mu}m$ diameter. In contrast to the conventional macroscopic-sized-billet fine-wire requires higher extrusion pressure and effect of friction is much more significant.

• Tribology and Lubricants
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• v.25 no.3
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• pp.182-186
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• 2009

Extruders can be basically divided into bisk and screw type of extruders. Though plastic extruders are often used for its simplicity for water and oil transportation pumps, these days screw extruders are mostly used. Screws are used in many extrusion processes to manufacture complex and complicated shaped parts made of plastics, medicine materials, food, polymer composites, iron and ceramic powders, etc. Also, material correction of deformities is caused by flow and physicochemical reaction phenomenonand material extrusion is processed according to heat transfer. various material comes to hopper because extruder has function by blender and mixing of materials can go well before come out through dice. These change process is so complicated that process condition is decided by trial and error that process condition is underground mainly at extrusion molding process.