Newest Developments on the Manufacture of Helical Profiles by Hot Extrusion

Author(s):  
Nooman Ben Khalifa ◽  
A. Erman Tekkaya

A new innovative direct extrusion process, helical profile extrusion (HPE) is presented, which increases the flexibility of aluminum profile manufacturing processes. The application fields of such profiles can be seen in screw rotors for compressors and pumps. The investigations concentrate on experimental and numerical analyses by 3D-FEM simulations to analyze the influence of friction and the material flow on the twisting angle and contour accuracy. By means of finite-element method (FEM), the profile shape could be improved by modifying the die design. The numerical results were validated by experiments. For these investigations, a common aluminum alloy AA6060 was used. Mainly, the friction in the die influences the twist angle and the shape of the helical profile. Two die coatings were analyzed, but the friction was not substantially decreased in any of these cases. Although there is no efficient practical solution for reducing the friction in extrusion dies using tested die coatings, the required profile contour could be achieved by new die designing and by modifying the material flow. However, increasing the twist angle is limited due to geometrical aspects of this technology, namely, by the ratio of the volume to the contact area with the die for the displaced metal.

Author(s):  
Nooman Ben Khalifa ◽  
A. Erman Tekkaya

The paper presents a new innovative direct extrusion process, Helical Profile Extrusion (HPE), which increases the flexibility of aluminum profile manufacturing processes. The application fields of such profiles can be seen in screw rotors for compressors and pumps. The investigations concentrate on experimental and numerical analyses by 3D-FEM simulations to analyze the influence of friction on the material flow in the extrusion die in order to find out the optimal parameters with reference to the twisting angle and contour accuracy. By means of FEM, the profile shape could be optimized by modifying the die design. The numerical results were validated by experiments. For these investigations, a common aluminum alloy AA6060 was used. The accuracy of the profile contour could be improved significantly. However, increasing the twist angle is limited due to geometrical aspects.


2020 ◽  
Vol 841 ◽  
pp. 375-380
Author(s):  
Dastan Igali ◽  
Asma Perveen ◽  
Dong Ming Wei ◽  
Di Chuan Zhang ◽  
Almagul Mentbayeva

Coat-hanger dies are widely used in the extrusion of polymer sheets and films. However, when designing the flat film/sheet extrusion dies manufacturing companies still facing difficulties in achieving the flow uniformity of the polymer melt. This affects the product quality and tool life. This study examines the existing extrusion die design which is used in in the industry in Kazakhstan for polypropylene sheet production and proposes better geometry of a die. These die geometries will be tested for flow uniformity in terms of velocity and pressure at the outlet.


2012 ◽  
Vol 152-154 ◽  
pp. 301-305
Author(s):  
Jian Yi Pan ◽  
Yao Wang ◽  
Zhao Yao Zhou ◽  
Shou Bin Dong

In order to improve the service life of extrusion dies with long cantilever structure, a design scheme of porthole die for half-hollow profiles with long cantilever was introduced. Using numerical simulation method, compared with conventional method for the half-hollow porthole design method of a typical profile die model, the equilibrium of the material flow at the outlet, the stress and deformation of the die were analyzed in detail. With selection of the cantilever thickness shrinkage as the objective function, experiment was done to verify the result of simulating analysis. The results indicated that there was only little difference for the equilibrium of material flow between the two design schemes, but the stress load and deformation of the design scheme were greatly improved.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Bing Zhang ◽  
Wen Wang

With the rapid development of the shipping and the power industry, the demand for high-performance cupronickel alloy pipes is greatly increasing. The main processing methods of this alloy include semisolid ingot casting and deformation by hot extrusion. Many defects appear during the hot extrusion process for large diameter cupronickel alloy pipes, which results in considerable problems. Therefore, numerical simulation of hot extrusion for cupronickel alloy pipes before the practical production is of vital significance to properly determine the deformation parameters. In order to obtain the influence of processing parameters on the piercing extrusion process of large diameter cupronickel alloy pipe, metal flowing law under different deformation conditions was simulated and analyzed via employing a 3D FEM code. The results showed that piercing speed had no obvious influence on the cupronickel alloy billet. However, the friction had significant influence on the piercing process of cupronickel alloy billet: with the increase of friction coefficient, the temperature and the load increased.


Author(s):  
Antonios Lontos ◽  
George Demosthenous ◽  
Filippos Soukatzidis

The aim of this paper is to study the effect of extrusion parameters (extrusion speed and temperature), die geometry, and the application of appropriate coating materials on the extrusion dies in order to extend their working life. To achieve the above goal FEM techniques and experimental tests adopted and simulating and experimental results evaluated. In this way, special FEM software was used to set up the finite element model of the aluminum extrusion. As a billet material the 6061 aluminum was used, with a specific diameter and length. The extrusion process was modeled as isothermal, which means that the billet material preheated at the specific temperature and then it was pressured into the two different dies, with a specific extrusion ratio. The extrusion speed was varied between 0.5 to 1 mm/sec and the extrusion temperature varied between 400 °C to 500 °C. The extrusion angle of the two different dies was 9° degrees. The fillet radius at the top surfaces was selected to be 1 mm. The friction between aluminum material (billet) and the extrusion equipment was i) aluminum material and die 0.3, ii) aluminum material and ram 0.9 and iii) aluminum material and container equal to 0.96. Optimized algorithms of extrusion parameters were proposed regarding to the concluded simulating results. The results obtain from the simulation procedure help to the better understanding of the specific extrusion process, leading to better modification of the experimental procedure. In this way, experimental tests were conducted on special laboratory extrusion press using the two different die geometries coated with three different PVD coatings. By means of these experimental tests the additional working life of the coated dies, during hot extrusion process, was able to be evaluated. In addition, the three different coatings where tested by established quality procedures in order to determine their behavior on the material of the extrusion die.


2011 ◽  
Vol 491 ◽  
pp. 265-272 ◽  
Author(s):  
L. Li ◽  
F. He ◽  
X. Liu ◽  
Yan Lou ◽  
Jie Zhou ◽  
...  

In the present study, the evolution of the grain structure of a Mg-Al-Ca-based alloy during hot extrusion was simulated with the cellular automation method. The Laasraoui-Jonas microstructure model was used to describe the dislocation evolution inside crystallites during dynamic recrystallization. The parameters in the Laasraoui-Jonas model, such as the hardening parameter, recovery parameter and material constants, were determined from the flow stress-strain data obtained from hot compression tests using a Gleeble-1500 thermomechanical simulator. The extrusion process was simulated using a DEFORM 3D FEM code. The influence of ram speed on grain structure evolution was analyzed. It was found that the average grain size increases with increasing ram speed. Good agreements between the predicted and observed grain structures were achieved.


2008 ◽  
Vol 43 ◽  
pp. 81-88 ◽  
Author(s):  
Thomas Kloppenborg ◽  
Marco Schikorra ◽  
Jan P. Rottberg ◽  
A. Erman Tekkaya

This paper presents the results of investigations on topology optimizations in extrusion dies. The change of material viscosity of finite elements in the numerical model is utilized to allow or to block the material flow through the finite elements in simplified two-dimensional extrusion models. Two different optimization procedures are presented. In the first part of the paper dead zones in a flat and in a porthole die were improved by enhance the streamlining of the extrusion die. In the second part an evolutionary optimization algorithm has been used to optimize the extrusion die topology in order to reduce the difference between the strand exit velocities in a multi extrusion process. Finally, both methods were sequentially combined.


2008 ◽  
Vol 367 ◽  
pp. 55-62 ◽  
Author(s):  
Nooman Ben Khalifa ◽  
Dirk Becker ◽  
Marco Schikorra ◽  
A. Erman Tekkaya

New innovative direct extrusion process variants, curved profile extrusion (CPE), twisted profile extrusion (TPE), and hollow profile extrusion (HPE), which increase the flexibility of aluminum profile manufacturing processes, are presented in this paper. These processes are characterized by influencing the material flow inside the die so that the forming process is completed when exiting the die. On the one hand, three-dimensionally curved profiles are produced and analyzed by CPE regarding the accuracy, the influencing parameters, and the compensation strategies. On the other hand, TPE and HPE make it possible to manufacture helical profiles usable, for example, as screw rotors in fluid machinery.


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