Extrusion process and die mechanics from an operational and best practices standpoint. Thermal alignment; process control; extrusion metallurgy; quenching, heat treatment; process variables to support precision tolerances; planning and scheduling; tooling; die design, manufacturing and correction; die coating and cleaning; other related technologies.
ET Technical Papers are Subject to Copyright
Papers published by the Extrusion Technology for Aluminum Profiles Foundation ("ET Foundation") in The Proceedings of the ET Seminar are subject to copyright. No part of The Proceedings, including individual papers submitted by authors for The Proceedings, may be reproduced in any form without the express written permission of the ET Foundation.
Extrusion & Die Process Application (EP) Track
EP302 - A Novel Analytical Equation for Front Scrap Allocation in Direct Aluminum Extrusion
Tommaso Pinter, Almax Mori; Barbara Reggiani and Riccardo Pelaccia, University of Modena and Reggio Emilia; Lorenzo Donati and Sara Di Donato, University of Bologna, Italy
At the end of each process stroke, the back end of the old billet material that completely fills the die starts to interact with the front side of the new billet loaded into the press that is usually contaminated by oxides, dust or lubricant thus producing a transition zone that extends to a variable length. In the case of structural applications, it becomes then clear that the length of the profile marked by the charge welds need to be scrapped and an accurate prediction of this portion become mandatory. For this purpose, analytical equations are available in literature but they show poor predictability. On the contrary, several contributions have been proving that FEA is the most reliable approach to scrap prediction; however finite element analysis is seldom accessible to extrusion companies and therefore industry is still looking for a valid alternative. This paper presents a new user-friendly equation comparing quantitatively its predictions with numerical ones. Finally, the author describes how to use the novel equation at its best thanks to selected case studies.
EP307 - Evaluating Factors Affecting Profile Extrudability
Tony Da Silva, Apex Aluminum Extrusions, Canada
The productivity of the aluminum extrusion process is directly influenced by several elements including alloy, die design, extrusion parameters, and the dimensions of the profile. This paper aims to evaluate the relationships between extrudability and die pocket size, die bearing length, billet flow type, radii diameter of profile features, and the thick-thin ratio. To test the correlation between each variable, billets will be extruded at continuously varying extrusions parameters until failure. The differences between trials will then be recorded and analyzed. These tests will be repeated until we achieve a sizeable, relevant set of data involving all the aforementioned parameters. The results will then be analyzed and contrasted with each other in the hopes of rank-ordering the impact of each variable. Documenting the impact each component has on the extrusion process will better allow for the optimization of future projects by reducing failure rates and die redesigns.
EP311 - The Journey to Supply Automotive Grade Extrusions: Challenges and Solutions
Jerome Fourmann, Rio Tinto - Aluminium, USA; Jean-François Béland, National Research Council Canada, Canada; Paul Rometsch, Rio Tinto - Aluminium, Canada; and Nick C. Parson, Rio Tinto - Aluminium, Canada
Aluminum 6xxx-series extrusions are nowadays widely used in automotive structures and crash management systems thanks to their remarkable characteristics. By taking advantage of the virtually unlimited cross-section design flexibility, extrusion shapes are seamlessly integrated with the end-product design requirements. Alloy/Temper selection can be more complex than other markets, as standard T6 tempers are often not compatible with target tensile properties. In addition, most automotive manufacturer specifications define minimum levels of ductility, measured by bend or crush testing, along with thermal stability and corrosion resistance. The choice of grain structure i.e., recrystallized or non-recrystallized can influence the balance of these properties. The extrusion processing conditions, in particular press quenching, can also play a significant role. Last but not least, the choice of alloy dictates the potential extrusion speed, shape design, and production cost. Strategies for alloy/temper selection based on all these requirements are discussed for a range of characteristics and strength levels.
EP313 - Fundamentals of Productivity Improvement in an Aluminum Extrusion Plant
Pradip K. Saha, The Boeing Company, USA; Numpon Mahayotsanun and Pongsak Tuengsook, King Mongkut’s University of Technology; and Sedthawatt Sucharitpwatskul, National Metal and Materials Technology Center, Thailand
The productivity improvement in an aluminum extrusion plant begins with the input parameters including extrusion shape and geometry, extrusion press selection, need of best die design and manufacturing, billet alloy, size, heating, and temperature control and finally ends with the right selection of press control variables to study the effect press control variables on die performance. This paper provides some fundamental approach of introducing and conducting design of experiments (DOE) for the aluminum extrusion plant to improve an overall productivity. Developed an initial DOE to analyze the current production practice by exploring the effect of input parameters and extrusion press control variables on the die performance to improve extrusion productivity at various stages by determining the maximum billet length to optimize extrusion runout with minimum scrap for each die, initial set of billet temperature and ram speed to optimize extrusion time. The second DOE was developed to improve the overall productivity by optimizing the ram/extrusion speed by monitoring exit extrusion and die temperature. Conducted DOE test trials in a production environment with set of dies designed with best die design parameters simulated by using finite element modeling (FEM) software and analyzed the test data to compare the productivity improvement of each die with the current production practice.
EP315 - Connecting the Dots to Achieve Optimization, Not Just Efficiency
Craig R. Werner, Werner Extrusion Solutions; and Jerome Fourmann, Rio Tinto – Aluminium, USA
The extrusion process and industry is relatively simple to understand and inexpensive to enter. The ability to serve markets is often controlled by the equipment, process and technical capabilities possessed; many companies possess sufficient levels of some but are lacking other key "connective tissue" that keep the the company from achieving the levels of performance required by customers. Uptime, Recovery, Productivity, Costs are important but gaps in capabilities or understanding the key linkages between all elements results in suboptimal performance. This paper addresses many key requirements from data to process, tooling and others required to achieve efficient operations and to progress from local optimizations to true global optimizations, moving the company from average toward "superextruder" performance. Data and technical understanding are core to pulling this off, and once achieved, it is far too easy to slide backwards through the loss of surprisingly few key understandings or achievements. The authors will document many of the key aspects like temperature, flow stress and pressures through the lens of data and disclose why excellent tooling or processes taken alone cannot lead to excellence.
EP318 - Quench Sensitivity of Automotive Extrusion Alloys
Nick Parson, Rio Tinto – Aluminium; Jean-François Béland, National Research Council Canada, Canada; and Jerome Fourmann, Rio Tinto - Aluminium, USA
Al-Mg-Si extrusions are widely used in automotive structures and crash management systems. In terms of material properties, a high yield strength is desirable for downgauging combined with superior ductility to accommodate plastic deformation associated with part forming, mechanical joining and crash with minimal cracking. The role of press quench is well recognized and water spray quenching is typically applied. The authors previously established a preferred minimum quench rate of 50°C/sec. However, the size and complexity of recent profile designs, e.g., for battery enclosures, can result in excessive distortion at high quench rates. It is therefore important to understand the material performance trade-offs with sub-optimal quenching. A test program was conducted using a purpose built “quench simulator” to study the effect of quench rates in the forced air to spray regimes for a range of commonly used automotive alloys. Strength and ductility were quantified by tensile and bend testing.
EP325 - Effects of Extrusion Process Parameter Variations on Mechanical Properties of AA6063 and AA6061
Paul A. Rometsch and Nick C. Parson, Rio Tinto – Aluminium, Canada; and Jerome Fourmann, Rio Tinto – Aluminium, USA
Among the many 6xxx-series aluminum extrusion alloys on the market today, AA6063 and AA6061 are well known as high-volume soft and medium strength alloys, respectively. For a given one of these alloys, different mechanical properties can be achieved depending on (i) how well the extrusion process parameters are controlled on a given press line, and (ii) the extent of a process deviation in the event of an unforeseen problem such as a delay on the press. This work explores how the peak-aged tensile properties, hardness and VDA bend performance of an extruded strip are influenced by deviations in key process parameters such as billet pre-heating rate, billet pre-soak time, and press delay duration over a wide range of billet temperatures, tooling temperatures and extrusion speeds. The work reveals processing windows where the mechanical properties of each alloy are relatively robust to process deviations.
EP358 - Use of Calibration to Achieve Tight Tolerances in High-Strength and Ductile Automotive Profiles
Jon Møretrø, Ulf H. Tundal, Stig Tjoetta, and Frode Paulsen, Hydro Aluminium Metal, Norway
The increasing use of aluminum extrusions in vehicles leads to higher requirements for alloys with the combination of high strength and ductility. In the extrusion process, such alloys typically need rapid cooling to gain the required final product properties. Additionally, the content of EOL-recycled aluminum is increasing, often accompanied by allowing larger alloying windows. Together, these factors are affecting the geometrical stability of the extruded profile, making it difficult to reach typical automotive tolerances without the need for excessive machining. In this presentation, strategies and methods for calibration of automotive extrusions are presented and discussed, with special focus on new alloys combining high strength, ductility and excellent extrudability. It is demonstrated that even with a high cooling rate and a high content of EOL-recycled material, tight automotive tolerances can be achieved from the extruded profile without machining by selecting the correct calibration method.
EP361 - Importance of Temperature in Extrusion Technology
Padavu Devaraj, Jindal Aluminium Limited, India
Aluminum extrusions produced by hot extrusion process are being used in a wide variety of industrial and domestic applications. There are many parameters that influence the extrusion process, such as temperature, extrusion ratio, extrusion speed, die design, profile shape, and many others. One of the most important parameters in the hot extrusion process is the temperature at different stages. In the competitive market driven by price and quality, one of the main objectives is to extrude at the maximum possible speed in order to achieve the best productivity and quality. To achieve this, it is crucial to maintain the right temperature for the billet, die and container during the entire process. Temperature also plays a key role to improve the press efficiency, product quality and to reduce die wear. This study covers the influence of billet temperature, profile exit temperature, container and die temperature on the extrusion quality and productivity.
EP363 - Improving the Soundness of Seam Weld Joints in Hollow Profiles
Raghavendra Rao Kulkarni and B. Nataraja, Jindal Aluminium Ltd., India
Extrusion of hollow profiles through hot extrusion of Aluminium frequently poses a challenge to ensure the soundness of the weld joints. Various process parameters like profile design, die design, billet temperature, profile exit temperature, alloy composition, homogenizing, extrusion speed, extrusion ratio, etc., influence the soundness of the weld joint in a hollow profile. However, the role of die design is most vital to achieve a sound weld joint. In this article, we have shared our practical experience and approach towards the problems faced in some hollow profiles and how we were able to overcome these problems and achieve sound weld joints using a simulation software to validate the die design. We used our extrusion press of 279mm diameter for this study.
EP375 - The Role of AI in Digitalizing Die Correction – Processing Die Design Features and Aluminum Flow Behaviors through Neural Networks to Enhance Die Correction Intelligence: Part II
Praveen Cl Hewage, Benteler Automotive Raufoss, Norway and Craig R. Werner, Werner Extrusion Solutions LLC, USA
The worldwide extrusion industry is losing critical die designer and technician knowledge and skills through attrition. Training and mentoring to achieve fully competent die technicians take 8-10 years, highlighting the need to improve knowledge and skills transfer. We must explore modern technologies such as artificial intelligence (AI) to secure and enhance extrusion tooling training and effectiveness. This paper addresses applying AI to characterize die designs based on design features using OCR and profile conditions and resultant flow behaviors based on these critical design features through self-learning algorithms, suggesting root causes and process or die correction solution options. These options will only highlight specific design features to consider instead of exposing entire profile drawings, which will minimize any fear of copyright violations issues, allowing the extrusion community to benefit. The road forward will require cooperation but will help to ensure and uplift our critical industry capabilities and skills.
EP378 - Modeling the Effect of Composition and Billet Temperature on Extrudability and Properties of AlMgSi Alloys
Ole R. Myhr, Hydro Aluminium R&D; Anders Nesse, Hydro Extrusions; Mads Iddberg, SINTEF Manufacturing; and Trond Furu, Norsk Hydro, Corporate Technology Office, Norway
In the present article, model simulations are used to predict the effect of alloy composition and billet pre-heat temperature on extrudability, tensile properties, and grain structure of 6xxx-series extrusions. When the extrusion speed is limited by hot-tearing, a decrease in billet temperature tends to increase the maximum extrusion speed before incipient tearing occurs. In contrast, the resulting yield stress after aging is often reduced by a decrease in billet temperature. In addition, the combination of billet temperature, extrusion speed and homogenization heat treatment affect the recrystallized grain structure. These conflicting requirements to be considered in production of 6xxx-series aluminum extrusions have been attempted to be solved through process simulations using a combination of microstructure-based models and FE simulations. The simulation results have been validated by extrusion experiments for a range of 6xxx-series alloys and different homogenization cycles, and the overall agreement between simulation results and measurements was generally good.
EP393 - Optimization of Preheating Parameters and Improving Die Life for Nitrided Aluminum Extrusion Dies
Mehmet Emin Akar, ASAS Aluminum, Turkey
During annealing process in an air furnace, the nitride layer oxidizes. It causes a rough surface, flaking, and cracks the nitride layer.
In this study, air and inert furnace are compared for annealing. Specimens were annealed in an air furnace at 450°C for 6, 8, 12, 15, 20, 25, 30, and 40 hours, and two specimens were annealed at 450°C for 6 and 12 hours in an inert furnace. In addition, abrasion tests were performed on two specimens to determine the white layer's abrasion resistance.
Conclusion, even when nitrided specimens are annealed for 6 hours in an air furnace, an oxide layer forms on the white layer. Thickness of the white layer decreases after 12 hours of annealing. Specimens that anneal for 6 to 12 hours in an inert furnace are not damaged and do not oxidize as much as those that anneal in an air furnace. In an inert furnace, 5% of the oxide components are present, but this value is 20% in an air furnace.
EP399 - Thermally Controlled Container: An Integral Part of the Extrusion Production System that Must be Managed to Approach Maximum Efficiency
Yahya Mahmoodkhani, Pouyan Rahnama and Paul Robbins, Castool Tooling Systems, Canada
The container reinforces and enhances the function of the extrusion die. Only if the entire production process is considered as an integrated system, can maximum efficiency be approached.
Controlling container temperature plays an important role in extrusion productivity. Modern containers benefit from embedded heating and cooling systems. In this paper, the different container heating and cooling methods will be evaluated using simulation tools. A combination of finite element and computational fluid dynamics is used to simulate and evaluate different methods of container heating and cooling. The container design and material selection are discussed based on simulation results and experimental observations. A decision theory is also proposed for selecting container design and material based on the extruded alloy and process conditions.
Extruded profiles have become larger, more complex, thinner, and stronger to facilitate new designs and manufacturing methods.
This paper also predicts the next steps in Quick Response (QR) container design to meet the quality and productivity requirements in the near future.
EP401 - Tooling Material and Heat Treatment Challenges with Bigger Extrusions
Yahya Mahmoodkhani and Paul Robbins, Castool Tooling Systems, Canada; and Lukas Henke, Deutsche Edelstahlwerke Specialty Steel GmbH & Co. KG, Germany
H-13 quality is discussed, including several methods of melting hot work tool steel such as VAR, ESR, etc. An alternative material XLL Extra Long Life made by Swiss Steel Group is introduced. Heat treatment processes including vacuum versus atmosphere, horizontal versus vertical, tempering temperatures and pressurized gas quenching are examined. Many presses operate at high pressures with long billets. Therefore, stems and liners are quite long. These parts have specific challenges to prevent catastrophic failure. Simulation and experimental results show that vertical vacuum furnace gives more uniform heat treatment along the large cylindrical parts, compared to horizontal furnaces. Pressurized gas quench is simulated using Computational Fluid Dynamics (CFD) method to compare quench quality. Microstructure and hardness distribution of the large parts are compared. All steels and heat treat methods are not equal. People using these materials and services must be informed, and specifications created to make them reliable and safe.
EP402 - High-Performance Dies Consume Less Energy, Last Longer and Create Less Scrap
Yahya Mahmoodkhani and Paul Robbins, Castool Tooling Systems; and Terry Clarke, Exco Tooling Solutions, Canada
Function of the die is to give shape to the workpiece. This process imposes lots of work to the material, the majority of which converts to heat and remains in the workpiece and adds to the profile exit temperature. The most productive die is the one that adds the least amount of work to the workpiece or imposes the minimum amount of redundant work. In this paper, finite element simulation tools will be used to optimize the die design by applying a series of virtual die corrections on the original die model. The effect of different features of the die on exit temperature and extrusion load will be studied and the amount of possible ram speed gain will be estimated for each step of die correction. Die corrections studied in this paper consists of; removing control pocket, larger undercut, full round entry bridge, easy flow entry bridge, and dished-in bridges. In theory, eliminating these features can potentially improve the ram speed by close to 100%, which can be translated into more than a 50% improvement in net productivity. As long as the die is treated separately, maximum productivity cannot be achieved. In other words, the whole extrusion process must be treated as a system where all the parameters are important, such as die, container and billet preheat temperature, alignment, proper bolster conditions, etc. The use of a high productivity die is not possible without accurate die preheat and a thermally stable container liner. The die interacts with several other complimentary elements of the process. If the interacting elements are equally efficient, they will reinforce and enhance its function.
EP404 - Optimizing Die Design to Minimize Recrystallization in Extruded Aluminum Alloy Profiles
Ilyas A. Sari, Melih Caylak, Anil U. Ozdemir, Zeynep T. Ozen, Ercan Zayim and Gorkem Ozcelik, ASAS Aluminum A.S., Turkey
Recrystallization is a common phenomenon that occurs during manufacturing process of aluminum profiles, leading to grain growth and reduction in mechanical properties. This paper presents an investigation on the effect of die design modification on recrystallization behavior of extruded aluminum hollow profiles made of 6082 alloy. With modifications made, recrystallization zones were investigated, and their metallographic examination was carried out. Microstructures were analyzed using optical and scanning electron microscopes (SEM). It was found that die design had a significant effect on recrystallization behavior of extruded profiles. Specifically, location of die port bridges may cause large recrystallization zones. It is possible to reduce recrystallization by changing these locations. During extrusion, reduced deformation and shear stress in the material lead to a more homogeneous distribution of strain and a lower degree of stored energy. Results of this study provide important insights into optimization of die design for production of high-quality extruded profiles with improved mechanical properties.
EP409 - promex CT - Complicated Profile Measurement with No Sample Preparation
Brad Allen, iNOEX LLC, USA; Björn Biehler, ASCONA, GmbH, Germany; Markus Eberhorn and Tobias Schön, Fraunhofer Institute for Integrated Circuits IIS, Germany
Profile measurement for extrusion has been an exciting developing technology for years. Many extruders use optical measurement technology within the extrusion environment, to be able to give them the quickest results to affect process change. But even those highly capable technologies have limitations. Small complex features and sample preparation, especially with soft alloys, can still be challenging to the optical measurement process. ASCONA, in partnership with the Fraunhofer Institute, have developed the promex CT measuring solution using computerized tomography technology. In measuring an approximately 3-inch-long sample, with no end cut preparation, high resolution cross-sectional imagery provides exceedingly accurate measurements that have not been achievable in the past. Working closely with multiple European beta customers specializing in small, complex profiles, ASCONA is receiving valuable feedback that the promex CT solution has provided these customers with measurement results beyond any capability that they have experienced before.
EP428 - Recrystallization Effects on the Formability of Extruded AA6082-T6 Profiles
Xianyan Zhou, Sigmund Tronvoll, William M. Williams, Lise Sandnes and Torgeir Welo, Norwegian University of Science and Technology (NTNU), Norway
Industrial leaders are pushing toward high-efficiency manufacture of high-quality products through optimization of thermo-mechanical processes with respect to product properties. As part of this campaign, this paper investigates the influence of recrystallization on the formability of AA6082-T6 extruded profiles, as assessed via VDA 238-100 three-point bending tests. Different recrystallization levels are achieved by altering the homogenization and extrusion parameters while manufacturing rectangular hollow AA6082-T4 profiles, extruded through a dual-cavity die with both water and air quenching. The microstructure after aging was assessed via microscopy and shows that the achieved recrystallization extended mainly through the top and bottom quarter thickness, while extending through thickness for regions closer to the corners of the rectangular profile. The VDA-238-100 testing reveals that, while avoiding recrystallization is paramount for higher formability of air-quenched samples, the effect on water-quenched samples is much smaller in comparison.
EP445 - Increasing Productivity of Porthole Aluminum Extrusion Dies Through Finite Element Analysis and Liquid Nitrogen Use
E. Giarmas and I. Theodoridis, Alumil SA; P. Tounis and T. Pinter, Matrex Aluminum Dies S.A.; and D. Tzetzis, International Hellenic University, School of Science and Technology, Greece
Die design holds a vital role in producing high-quality aluminum extrusion products with the proper efficiency. Porthole dies are commonly used to produce hollow profiles for several industrial applications. However, many die design parameters can affect a profile’s surface quality, geometry, and productivity rates. The presented research studies one die with two holes. Aluminum alloy 6060 is chosen for numerical and experimental research. HyperXtrude software from ALUMAT SRL is used during the Finite Element Analysis phase. Experimental results utilize a 3750t extrusion press at ALUMIL SA. A liquid nitrogen system is also used to enhance die productivity rates. The initiative to make this study has been undertaken in order to provide some important guidance to other extruders in the direction of producing high-quality extrudates with parallel enhancement of productivity with the aid of Finite Element Analysis.
EP446 - Analyzing Die-Related Influencing Factors for Surface Defects in Aluminum Extrusion
Satheesan Unni and Noyal Sunny, Hindalco Industries Limited, India
In modern aluminum extrusion die failures are costly, with respect to the loss of press time and meeting the OTIF targets. Customers are focusing more on parameters like surface quality, and problems like junction lines are often unacceptable. Hence, the problem of die failure must be tackled with a combination of failure analysis and effective corrective procedures. This paper presents a systematic study on the various causes for die failure and methods to avoid/correct them based on the actual plant performance scenario. This includes proper methods of die correction/maintenance/ storage practices, recent developments in die design and correction. Additional focus is given to establishing a system for storing, organizing, and updating the extrusion feedback and correction data. This is done by utilizing digital modules for data collection and closed-loop feedback systems between press and die shop. Methods of improving die performance like nitrogen shrouding are also discussed.
EP456 - Understanding Aluminum Extrusion Die Heat-Treating and Nitriding to Reduce Failures and Lower Tooling Costs
Jack A. Kalucki, Nitrex Metal Inc., Canada
Extrusion dies undergo a series of heat-treating steps prior to manufacturing, followed by cyclic surface treatment to restore their hardness. Hot-work tool steels like H13 require proper through hardening while avoiding decarburization, and multiple tempers to ensure durability and stability at extrusion temperature. However, not all heat treatments are alike, and vacuum hardening is the safest method for thorough hardening without problems. Additionally, tempering at high temperatures requires vacuum or atmospheric furnaces with protective atmospheres and good uniformity.
In contrast, nitriding is part of a repetitive cycle. Ideally, the process should produce a perfect nitrided case with each cycle, with a compressive stress distribution aimed at minimizing die flaking and brittleness. This analysis offers proper heat treatment guidelines, describe types of heat-treat equipment commonly used for hardening/re-hardening extrusion dies, and explain methods to avoid costly defects in order to achieve the best die life and performance.
EP458 - Die Technology - Dynamic Die Design
Feroze Syed and Sajid Hussain, MJ DMCC, UAE
Despite exceptional developments in collaboration between die makers and extruders, there are still gaps between these two communities. R&D in die design is impacted due to this gap. One of the key factors in removing this gap is to educate die designers in die technology. In fact, die technology and extrusion technology should be a foundation subject for die designers to analyze the problem and effectively communicate with extruders. Continuous and honest feedback exchanges between the design community and extruders is the only way to bring about this change. Sometimes, the feedback received from extruders is biased. The design community should scrutinize the feedback with a scientific approach and apply this in the design innovation in conjunction with die technology. Salient topics in die technology and extrusion technology are highlighted, which add value to the aforementioned cause.
EP463 - Improvements in Caustic Soda Recovery from Extrusion Die Cleaning Plants
Lorenzo Vecchi and Ivano Fazioli, Italtecno Srl, Italy
In recent years, a lot of advanced technologies have been introduced in the extrusion industry regarding automatic die cleaning followed by caustic soda recovery as a unique Italtecno development.
Due to continuous price increases of caustic soda in the last years and considering also the ecological factors of chemical recovery, there has been an increasing demand for such technology.
In the present paper a background of the technology is presented followed by a description of latest innovative developments in the direction of a fully automatic operation and remote control of the plant.
EP466 - The Impact of Discoloration on Heat Transfer in 6xxx-Series Aluminum Log
Lucas Itchue and Jeffrey Victor, Hydro – Innovation & Technology, USA
The effects of dark discolorations on the surface of cast aluminum extrusion log have been noted to influence the heat transfer rate during extrusion preheating. It is believed that the dark surface alters the emissivity of the surface and causes it to heat up more rapidly than standard, silver in color log. This has the potential to have a negative effect on temperature control and add variation to the overall extrusion process. Most currently available results provide qualitative information only, without approximations of impact. Quantitative experimental analysis includes measurement of the heating and cooling rates of two log slices from the same cast, one with a dark surface discoloration and one without. Discolored log reached preheat temperatures (460°C) ~10–20% faster than standard log, reaching a maximum difference of 30.1°C–48.4°C during heat up and 20.5°C–23.2°C during cool down.
EP502 - Using Aluminum Extrusions as an Integral Design Feature in a High-Pressure Profile Spray Quench
Jan Guenter, extrutec GmbH, USA
Extrusions for various applications require properties only achievable with a modern high-pressure profile spray quench. One of the features of a modern extrusion quench is that the amount of cooling can be precisely controlled. Modulating the heat transfer coefficient is what allows reaction to the cooling requirements of a big variety of profiles. Using multiple nozzles with different flow rates in combination with modulating the water pressure provides for the widest range of products that can be quenched with one and the same equipment, while minimizing distortion. This paper introduces the patented Alpha Flex Technology. By using a two-cavity aluminum extrusion, different nozzles can be used in one nozzle stock, increasing the range of the achievable heat transfer coefficient.
EP514 - Quality Defects After Die Making
Hanif Hamzah, Press Metal Aluminum Holding, Malaysia
Extrusion dies are very important tools for extruders to see their performance. One of the most important things in the dies is the quality of the die making. The quality control of die making is mainly focused on the ability to make all the die details such as the bearing length, bearing clearance, dimensions, and die surface finish. This paper does not discuss die design accuracy, but rather, the ability of the die maker to make dies according to the specifications. Defects arising from the tool inspection are discussed and a remedial action is proposed for the solution. The defects occurring during die making, and their implications for extrusion defects with solutions to the die making defects are summarized.
EP528 - The Effect of Zinc and Magnesium Contents on the Surface Roughness of Extruded Al-Zn-Mg
Satoshi Miyazaki, Tadashi Minoda, Katsuya Kato, UACJ Corporation, Japan; and Kuniaki Dohda, Northwestern University, USA
In this report, the authors investigate the effect of added elements on the surface roughness of 7xxx-series aluminum alloy at the initial stage of extrusion. The surface roughness changed with the added amount of Zn and Mg. The surface roughness decreased with the added amount of decreasing Zn or increasing Mg. From the die-bearing observation after extrusion, the adhesion of aluminum to the die-bearing increased with the amount of Mg. The adhesion of Mg2Si to the die-bearing increased with the amount of Zn. These results suggest that uniform aluminum adhesion to the die-bearing effectively decreases the surface roughness.