scholarly journals Embedding of Alumina Reinforcing Elements in the Composite Extrusion Process

2008 ◽  
Vol 43 ◽  
pp. 9-16 ◽  
Author(s):  
Daniel Pietzka ◽  
Marco Schikorra ◽  
A. Erman Tekkaya
Keyword(s):  
Material Flow ◽  
Collaborative Research ◽  
Research Work ◽  
High Strength ◽  
Extrusion Process ◽  
Process Window ◽  
Experimental Investigations ◽  
Specific Behavior ◽  
Pressing Operation ◽  
Aluminum Profiles

Extruded aluminum profiles are essential for lightweight constructions in contemporary transport and automotive applications. The reinforcement of such aluminum-based profiles with high-strength materials offers a high potential for weight reduction and an improvement of functional and mechanical properties. In comparison to conventional composite extrusion using fiber or particle reinforced billets, the alternatively developed process for the embedding of endless reinforcing elements provides enormous advantages regarding extrusion forces, load-adapted reinforcement, and tool abrasion. In this extrusion process with conventional billets, modified tools with portholes are used to position reinforcing elements from outside the pressing tool and to embed them into the material flow during the pressing operation. This composite extrusion process is part of the research work started in 2003 and carried out within the scope of the Collaborative Research Center SFB/TR10. To increase the potential of composite extrusion with endless reinforcing elements, the manufacture of composite extrusion profiles with high-strength non-metallic alumina wires is planned. Due to the wires’ specific properties, e.g. high stiffness, their deflection behavior must be analyzed to guarantee a stable feeding-in process. In this paper the specific behavior of alumina reinforcing elements regarding the feeding-in process is analyzed by experimental investigations. The main influencing factors are determined and a process window is deduced.

Composite Extrusion of Thin Aluminum Profiles with High Reinforcing Volume

2013 ◽  
Vol 554-557 ◽  
pp. 801-808 ◽  
Author(s):  
Daniel Pietzka ◽  
Nooman Ben Khalifa ◽  
Stephanie Gerke ◽  
A. Erman Tekkaya
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
High Strength ◽  
Extrusion Process ◽  
Process Window ◽  
Extrusion Dies ◽  
Thin Aluminum ◽  
Lightweight Structure ◽  
Porthole Extrusion ◽  
Aluminum Profiles

Extruded aluminium profiles with a variety of different cross-sections are mainly used in lightweight structures for transportation means. Examples are stringer profiles in the fuselage of airplanes or profiles in chassis of trains and cars. Nowadays, the mass reduction of a lightweight structure is an important issue to achieve lower fuel consumption and CO2 emissions. With an increased portion of aluminium profiles the mass of structures can be reduced considerably in contrast to the application of steel parts, due to the lower density of aluminium. However, this is coupled with disadvantages such as the lower specific stiffness and strength of the material. One possibility to improve the mechanical properties of aluminium profiles without a considerable increase of their weight is the embedding of reinforcing elements during the extrusion process. Special porthole extrusion dies are used to feed reinforcing elements in form of high strength steel wires separate from the aluminium material flow. In the welding chamber of the die both materials bond together to a composite profile. To achieve a high advantage of the technology for lightweight applications a high reinforcing volume of aluminium profiles is targeted. A comparatively high reinforcing volume can be reached either by a high number of reinforcing elements or through a reduction of the profile wall thickness. A high number of reinforcing elements leads to a small distance between the single elements in the profile cross-section. The paper will show the results of an experimental and numerical analysis which were carried out to determine the minimum distance between the reinforcing elements as well as the minimum profile thickness. In the trials different arrangements of the elements in the profile cross-section and profile thicknesses were considered. Main parameters which have an influence on the process stability were analyzed and a process window for the manufacture of thin profiles with high reinforcing volume was deduced.

Improved Extrudability of High Strength Alloys Using an Optimization Method Based on a Combination of Experiments and FEM Software

2013 ◽  
Vol 585 ◽  
pp. 165-171 ◽  
Author(s):  
Stanka Tomovic-Petrovic ◽  
Rune Østhus ◽  
Ola Jensrud
Keyword(s):  
Material Flow ◽  
Silicon Content ◽  
High Strength ◽  
Optimization Method ◽  
Extrusion Process ◽  
Model Alloy ◽  
Process Variables ◽  
Die Geometry ◽  
Simulation Results ◽  
6Xxx Series

Numerical analysis of the material flow during the extrusion process for high alloyed variants of the AA 6xxx series is presented in this paper. The analysis was performed by using the commercial FE code Forge2011®. Another issue considered in the paper was an interrelation between the die geometry and the critical extrusion process variables. For optimization of the die exit geometry, the model was produced with the use of linked equation in SolidWorks® combined with Mode FRONTIER. Several extrusion trials were performed to provide a basis for the verification of simulation results as extrusion temperature, speed and force. For the purpose, rods of a model alloy designated as AlMgSi4, based on an industrial AA6082 aluminium alloy with significantly higher silicon content, were extruded. A good correlation between measured and calculated results was obtained. This approach may enable simplifying when dealing with design of a new alloy.

Seam Weld Positioning for Composite Extrusion

2006 ◽  
Vol 10 ◽  
pp. 101-110 ◽  
Author(s):  
Marco Schikorra ◽  
Matthias Kleiner
Keyword(s):  
Material Flow ◽  
Base Material ◽  
Extrusion Process ◽  
Velocity Fields ◽  
Experimental Investigations ◽  
Local Perturbation ◽  
Seam Weld ◽  
Element Simulation ◽  
Development Area

The production of continuously reinforced profiles by use of aluminium as base material and a reinforcement made of steel or carbon offers a great potential for modern lightweight constructions. Within this scope, they present the potential for an increase in usage of space frame constructions in automotive or aerospace engineering. But with the insertion of reinforcement in the material flow of the extrusion process some problems can occur that are negligible in thee conventional extrusion processes: in the composite development area a significant local perturbation of the material flow is induced that can lead to the induction of high tensile stresses into the reinforcement. Due to this, failures like cracking of the reinforcement elements during the extrusion process has been detected in experimental investigations. A second problem occurring is the necessity of prediction of the seam weld position and prediction of the seam weld quality. The reinforcement can only be induced by bridge dies between two strands and due to this it is always positioned in a seam weld. While in conventional extrusion the seam weld positions is often only an aesthetical problem, now this position mainly influences the extruded profiles properties like moment of inertia. This paper deals with the problem of determination of seam weld position on the example of a double-t-profile extrusion. By use of a coupled thermo-mechanical finite element simulation with the commercial FE code HyperXtrude from Altair the velocity fields of an extrusion process with and without reinforcement were calculated and the resulting material flow was analysed. The numerical results went along with experimental investigations to verify the calculated results.

Numerical Approach for the Evaluation of Seam Welding Criteria in Extrusion Processes

2012 ◽  
Vol 504-506 ◽  
pp. 517-522 ◽  
Author(s):  
Martin Schwane ◽  
Thomas Kloppenborg ◽  
Andreas Reeb ◽  
Nooman Ben Khalifa ◽  
Alexander Brosius ◽  
...  
Keyword(s):  
Automobile Industry ◽  
Numerical Approach ◽  
Extrusion Process ◽  
Experimental Investigations ◽  
Welding Quality ◽  
Seam Welding ◽  
Numerical Investigations ◽  
Welding Line ◽  
Aluminum Profiles ◽  
Longitudinal Seam

The accurate simulation and the optimization of extrusion processes can be a helpful technique to ensure producibility of complex aluminum profiles, for example for the automobile industry. Currently, the die designing is based on expert’s knowledge and cost-intensive prototyping. The paper deals with numerical investigations based on finite element simulations as well as experimental investigations of an industrial extrusion process. A newly developed method for longitudinal seam weld prediction is applied to analyze the position of the longitudinal welding line and the welding quality.

Experimental Investigation of Heat-Treated Aluminum Profiles

2015 ◽  
Vol 651-653 ◽  
pp. 59-64
Author(s):  
Marion Merklein ◽  
Matthias Graser ◽  
Michael Lechner
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Experimental Investigation ◽  
Material Flow ◽  
Material Characterization ◽  
Process Window ◽  
Short Term ◽  
Property Distribution ◽  
Heat Treated ◽  
Aluminum Profiles

Tailor Heat Treated Profiles (THTP) are profiles that exhibit local different mechanical properties optimized for a subsequent forming operation. The property distribution is realized by short term heat treatment before a forming operation. Based on the interaction of soft and hard areas the material flow can be improved and the formability can be enhanced. Prerequisite for a successful application of the technology is a comprehensive material characterization. Therefore, within this paper the influence of short term heat treatment on the mechanical properties of profiles will be presented. In particular, different heating technologies based on heat conduction and laser radiation are compared. Based on the results, a process window will be derived. All investigations were performed using the precipitation hardenable aluminum alloy EN AW 6060.

Numerical Optimization of Bearing Length in Composite Extrusion Processes

2008 ◽  
Vol 367 ◽  
pp. 47-54 ◽  
Author(s):  
Thomas Kloppenborg ◽  
Marco Schikorra ◽  
Michael Schomäcker ◽  
A. Erman Tekkaya
Keyword(s):  
Material Flow ◽  
Numerical Optimization ◽  
Optimization Technique ◽  
Base Material ◽  
High Strength ◽  
Optimization Method ◽  
Extrusion Process ◽  
Simulation Based ◽  
Small Ratio ◽  
Simulation Based Optimization

The decrease of the bearing length in extrusion processes results in increasing of the material flow and offers, through this, the possibility for manipulation and optimization. This paper presents a simulation based optimization technique which uses this effect for optimizing the material flow in direct extrusion processes. Firstly, the method is used in a multi-extrusion process with equal pitch circle profiles, then in an extrusion process of an asymmetric profile. Furthermore, a composite extrusion process is analyzed where endless wires of high strength steel are embedded in a base material of aluminum. The insertion of reinforcement elements into the base material flow, especially within the small ratio between profile thickness and the reinforcement diameter, can lead to significant local disturbances inside the die, which result in undesirable profile defects. Hence, the simulation-based optimization method is especially used to optimize inhomogeneous wall thicknesses in composite profiles.

scholarly journals Numerical and experimental investigations for distortion-reduced laser heat treatment of aluminum

2021 ◽  
Author(s):  
Nikolaos Rigas ◽  
Marion Merklein
Keyword(s):  
Heat Treatment ◽  
Material Flow ◽  
Treatment Strategies ◽  
High Strength ◽  
Local Heat ◽  
Experimental Investigations ◽  
Heat Treated ◽  
Local Softening ◽  
Materials Used ◽  
Automated Handling

AbstractIn the field of mobility, increased safety and emission requirements lead to steadily rising demands on materials used and their performance. Over the last decades, 5000 and 6000 series aluminum alloys have become more and more attractive as lightweight material due to their beneficial weight to strength ratio. The 7000 series offers extended lightweight potential due to its high strength. Until now, this class of alloys has not been widely used in mass production due to its limited corrosion resistance and poor forming behavior. By using so-called Tailor Heat Treated Blanks, it is possible to set increased forming limits of previously locally heat treated components. The reason for the enhanced formability is the local softening, with the resulting improved material flow and the reduced critical forming stresses of the sheet metal before the forming operation. Despite these advantages, the use of previously heat treated materials has been very limited so far. For example, the distortion that occurs during local heat treatment reduces geometrical accuracy and thus automated handling. Therefore, the focus of this thesis is the investigation of tailored heat treatment strategies, permitting a distortion-reduced local short-term heat treatment. For this purpose, the distortion behavior is represented and quantified both numerically and experimentally. The generated knowledge is then transferred to a large volume component and characterized.

Process Window Determination for Thixoextrusion Processes Using a Steel Alloy

2008 ◽  
Vol 141-143 ◽  
pp. 61-66
Author(s):  
Frederik Knauf ◽  
René Baadjou ◽  
Gerhard Hirt
Keyword(s):  
Material Flow ◽  
Solid Material ◽  
Extrusion Process ◽  
Process Window ◽  
Steel Alloy ◽  
Channel Diameter ◽  
Feed Stock ◽  
Temperature Development ◽  
Process Mechanics ◽  
Semi Solid

A direct semi-solid bar extrusion process is characterised by inserting a feed stock in a container and extruding through a forming die with a punch. Compared to conventional bar extrusion the use of semi-solid material complicates the process due to the requirement of solidification of the material. To achieve the solidification of the semi-solid bar, different basic tool concepts are presented. With a combination of these concepts experiments were carried out using the steel alloy X210CrW12 to detect the influence of the most influencing parameters press velocity, extrusion channel diameter, length and geometry. Numerical simulations enable a better understanding of the process mechanics like temperature development in the billet and forming die as well as the material flow in the deformation zone.

scholarly journals Corrosion Behaviour of High-Strength Al 7005 Alloy and Its Composites Reinforced with Industrial Waste-Based Fly Ash and Glass Fibre: Comparison of Stir Cast and Extrusion Conditions

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3929
Author(s):  
Praveen Kumar Swamy ◽  
Shantharaja Mylaraiah ◽  
Manjunath Patel Gowdru Chandrashekarappa ◽  
Avinash Lakshmikanthan ◽  
Danil Yurievich Pimenov ◽  
...  
Keyword(s):  
Fly Ash ◽  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Research Work ◽  
Glass Network ◽  
High Strength ◽  
Stir Casting ◽  
Extrusion Process ◽  
Industrial Wastes

The stringent demand to develop lightweight materials with enhanced properties suitable for various engineering applications is the focus of this research work. Industrial wastes such as fly ash (FA) and S-glass-fibres (GF) were used as reinforcement materials for high-strength alloy, i.e., Al 7005. Stir casting routes were employed for fabricating the four samples, Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA. The extrusion process with different extrusion ratios (ER: 5.32:1, and 2.66:1) was used to examine the properties of all four samples. Extruded samples with ER: 5.32: 1 resulted in equiaxed grains with refined structure compared to stir casting parts. The effect of the extrusion process and the addition of reinforcements (GF and FA) on the gravimetric, electrochemical, and electrochemical impedance corrosion behaviour of Al 7005 composites in 1M HCl (Hydrochloric acid) solution were investigated. The results of all three corrosion methods showed that Al 7005 + 6% FA exhibited higher corrosion resistance. Corrosion rate of Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA is found equal to 3.25, 2.41, 0.34, and 0.76 mpy, respectively. The FA particles remain inert and act as a physical barrier with corrosive media during the corrosion test. GF undergoes fibre degradation or disrupts the continuity of the glass network as a result of fibre leaching, which increases the corrosion rate in the sample. The gravimetric study showed that the corrosion rates decreased with an increase in extrusion ratio, which might be due to corrosion passivation increases and improved properties. The scanning electron microscopy reveals that corrosion fits, flakes and micro-cracks were observed more in the as-cast composites than that of extrusion composites, promoting the corrosion rate.

Influence of Heating Models on Necking Deformation during Tube Extrusion Process

2011 ◽  
Vol 189-193 ◽  
pp. 1778-1781 ◽  
Author(s):  
Gui Hua Liu ◽  
Yong Qiang Guo ◽  
Zhi Jiang
Keyword(s):  
Temperature Gradient ◽  
Material Flow ◽  
Extrusion Process ◽  
Work Piece ◽  
Tube Extrusion ◽  
Deformation Parameters ◽  
Flow Features ◽  
Extrusion Forming ◽  
3D Software ◽  
Deform 3D

By using Deform-3D software, the necking extrusion forming processes of integer trailer axle with two different heating means which are Uniform Heating (UH) method and Partly Heating (PH) method with temperature gradient are simulated. The influence of deformation parameters such as friction factor, necking coefficient, different temperature distribution of work-piece on the material flow features, stress and strain field, loading force and deformation process are analyzed in detail. According to the numerical simulation results, using PH method with temperature gradient can improve necking deformation during tube extrusion process.

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