• Transactions of Materials Processing
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• v.13 no.8
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• pp.689-695
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• 2004

This paper is concerned with the analysis of the forming load characteristics of a forward-backward can extrusion process. The analysis in this paper is extended to the selection of press frame capacity for producing efficiently final product at low cost. The possible extrusion processes to shape a forward-backward can part with different outer diameters are categorized to investigate quantitatively the forming load, forming energy and maximum pressure exerted on the die-material interface. The categorized processes are composed of combined and/or some basic extrusion processes. After the analysis of the forming load characteristics, the frame capacity of press suitable for a selected process could be determined along with securing the load capacity and with considering productivity. In addition, it is also suggested that different load capacities be selected for different dimensions of a part such as the wall thickness in forward direction. The work in this paper could be a good reference for analysis of complex extrusion and selection of proper frame capacity of press to achieve low production cost and thus high productivity.

• Clean Technology
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• v.27 no.4
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• pp.297-305
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• 2021

In the domestic aluminum industry, the extrusion process is a major process accounting for more than 40% of the total production. However, most domestic aluminum extrusion companies produce aluminum using old equipment that is more than 30 years old. Extrusion press is when the equipment is not replaced before the wear and breakage of major parts occur, reducing productivity and increasing the defect rate compared to new equipment. The old extrusion press often loses part drawings, so it is difficult to repair them properly on-site and to remanufacture them due to the lack of technical skills for maintenance. Therefore, a systematic remanufacturing plan must be designed from dismantling the equipment. In this study, remanufacturing FMEA was devised to remanufacture old extrusion press. The risk priority was analyzed by considering the degree of damage to the recycled parts, the cycle due to breakage/damage during the extrusion process, and the value of recycling resources due to remanufacturing. To standardize the remanufacturing process, remanufactured FMEA was performed through part analysis according to the structural analysis of the extrusion press. In addition, remanufacturing priorities were selected for each part, while remanufacturing itself was studied for efficiency of resource circulation and product quality stabilization.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.846-849
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• 2000

In this paper backward extrusion process with lower die rotation was studied to improve the conventional backward extrusion problems ; requirement of large forming machine, the difficulty to selecting of die material caused by high surface pressure, high cost of forming machine caused by improvement of noise and vibration, and etc. In this experiment, model material, plasticine, was used of specimen. The result values of torsional and conventional backward extrusions were analyzed and compared. FE-simulation is used for analysis with DEFPRM-3D. These results show that the torsional backward extrusion is very useful process because this process can obtain the homogeneous deformation, low forming load. Decreasing forming load improves die life and makes it possible to use press of relatively low capacity. Also this process can reduce corner cavity, improve the initial cast-structure, owing to the high deformation and uniform starin distribution.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.266-269
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• 2005

The effect of exit temperature on the thickness of recrystallization layer during Al extrusion process was investigated. The recrystallization layer of an extruded Al alloy is an important feature of the product in a wide range of applications, particularly those within the automotive industry. The thicker recrystallized layer in the Al alloys can give rise to a number of problems including reduced fatigue resistance and orange peel during cold forming. But the interaction of extrusion process variables with the thickness of recrystallization layer is poorly understood, and there is limited information available regarding the role of the main hot extrusion variables. Using the 3650 US ton extrusion press, this paper describes the effect of the main process variables such as billet temperature, ram speed, and exit temperature on the thickness of recrystallization layer for the A6XXX Al alloy.

• 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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• 1996.03b
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• pp.130-137
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• 1996

Several cold extrusion processes to produce an axisymmetric steel piston-pin are investigated for comparing each other. Two methods among four conventinal ones are selected to be simulated using the rigid-plastic finite element method. One of the both methods using a mechanical press has one stage process and the other utilizing a cold header applies a multi-stage process to produce a final product. Because the main process is a backward extrusion, the design criteria such as the backward extrusion ration and punch diameter to depth rationare ocnsidered. FEM analysis is performed mainly for strain distributin and load-stroke relationshis. Based on the results of preliminary simulatin, both process sequences are proved to have proper charicteristics suitable for each production method in terms of maximum load. Those simulation results will be a good design criteria in the future work to advance the manufacturing process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.76-81
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• 2021

A plastic noise barrier is a structure installed to minimize noise, and it is composed of the main plate, sound-absorbing plate, and sound-absorbing material. Plastic noise barrier structures have several advantages compared to other products, such as light weight, anticorrosion, durability, easy assembly, rapid construction, and low costs. In this study, the main and sound-absorbing plates were manufactured through extrusion molding, and the sound-absorbing plate was finished with a press to improve the conventional injection molding. Extrusion molding dies and punch dies were designed, and a profile extrusion-molding system was developed. Thus, inexpensive and efficient sound-absorbing and main plates can be produced, and the noise barrier structure can be assembled rapidly. Additionally, a noise barrier structure with extended service life and excellent quality can be constructed by creating uniform free space to accommodate increased temperatures after assembly and installation.

• Transactions of Materials Processing
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• v.13 no.5
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• pp.422-428
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• 2004

At present, the design of extrusion dies and operation in extrusion companies are primarily based on trial and error. The experience of the die designer, the press operator and the die corrector determine the performance of the extrusion die and the efficiency of the process. In order to produce defect-free products of desirable quality in terms of strength, surface quality and geometrical dimensions, it is important to obtain more knowledge of the processes that occur during extrusion. Recently, to reduce the costs of designing and manufacturing of extrusion dies, and to ensure the quality of the extruded products, numerical simulation for extrusion processes such as FEM (finite element method) is applied increasingly and becomes a very important tool for the design and development of new products. However, most of the studies about FE simulation have been accomplished for simple geometry and low extrusion ratio in the filed of steady metal flow conditions. The extruded products of AI alloy in industrial practice involve complicated sectional geometry. This study was designed to reduce the time of die design and manufacturing in the extrusion process using FEM simulation. FEM simulations of extrusion process were performed in non-steady states conditions by changing weld plate included in extrusion die set. Product which was employed in this study is heat sink that has been used in the parts of heat exchanger of electric circuits. It is generally applied for aluminum or its alloys due to heat efficiency and easy production of complicated shapes, and manufactured by extrusion process. The simulated results showed that weld plate shape in extrusion dies influences meta] flow and dimensional accuracy of products.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.2
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• pp.141-148
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• 2017

A process comprising a hot extrusion process and a warm forging process was designed to form a T-shaped aluminum structural component with a high degree of difficulty by the plastic forming method. A circular cylindrical part was extruded with a hot extrusion process, and then an embossing part was formed with a warm forging process. The formability and the maximum load required for forming were then determined using a forming analysis program. The hot extrusion process was executed at $450^{\circ}C$ under the extrusion speed at 6 mm/s, while the warm forging process was executed at $260^{\circ}C$ under the forging speed at 150 mm/s. For both the processes, a condition by which friction would not be generated between the mold and the material was implemented. The analysis results showed that the load required for hot extrusion was 1,019 tons, while the load required for the warm forging was 534 tons. The T-shaped part was manufactured by using a 1,600 tons capacity press. The graphite lubricant was coated on the mold as well as the material. A forming experiment was performed under the same condition with the analysis condition. The measured values from the load cell were 1,210 tons in the hot extrusion process and 600 tons in the warm forging process.

• Transactions of Materials Processing
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• v.9 no.2
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• pp.171-178
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• 2000

This paper is concerned with the optimization of the drive for linear-guide press which is one of mechanical presses. The design of linear-guide drive for a mechanical press is introduced and the drive for the linear-guide press is optimized for the improvement of load and velocity characteristics. As a result of optimization, the load capacity during stroke increases and the slide velocity decreases in working region, respectively. The new design could be suited to many applications in precision forming such as extrusion and the sheet metal-forming processes.