Hot Extrusion of Thin-Wall Multichannel Copper Profiles

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Frank F. Kraft ◽  
Jonathan Kochis
Keyword(s):  
Heat Exchangers ◽  
High Efficiency ◽  
Hot Extrusion ◽  
Cold Drawing ◽  
Extrusion Process ◽  
Thin Wall ◽  
Channel Design ◽  
Extrusion Dies ◽  
Computer Controlled ◽  
Isothermal Extrusion

This paper presents the development of a unique, net shape, hot-extrusion process to produce precision, thin-wall, multichannel copper profiles for high efficiency heat-exchangers. This process is a departure from conventional copper extrusion, which is a nonisothermal process used primarily to produce simple semifinished products and hollow profiles requiring cold drawing after hot extrusion. A lab-scale apparatus was developed to simultaneously extrude multiple heated billets through a porthole type hollow die to form the multi-channel profiles. The process is performed at 700–750 °C, essentially at isothermal extrusion conditions. Temperature and tooling strength considerations necessitated the use of superalloys for the apparatus (which included dies, container, ram stems, and support tooling). A 250 kN computer controlled servo-hydraulic MTS® machine was used to provide the extrusion ram force. Two part designs were extruded to demonstrate process feasibility and versatility. A two-channel design with 0.2 mm wall thicknesses and an 11-channel design with wall-thicknesses of 0.3 mm were extruded. The extrusion ratios for these profiles are 67 and 25, respectively. Experimental data and an approach to analytically model the process are presented. Because solid-state welds in the tube walls are necessitated by the use of hollow extrusion dies, the microstructure in these regions is also presented.

scholarly journals Friction-Induced Recycling Process for User-Specific Semi-Finished Product Production

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 663
Author(s):  
Thomas Borgert ◽  
Werner Homberg
Keyword(s):  
High Efficiency ◽  
Research Work ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Efficient Production ◽  
Secondary Aluminum ◽  
Shape Accuracy ◽  
Aluminum Chips ◽  
Spinning Process ◽  
Complex Parts

Modern forming processes often allow today the efficient production of complex parts. In order to increase the sustainability of forming processes it would be favorable if the forming of workpieces becomes possible using production waste. At the Chair of Forming and Machining Technology of the Paderborn University (LUF) research is presently conducted with the overall goal to produce workpieces directly from secondary aluminum (e.g., powder and chips). Therefore, friction-based forming processes like friction spinning (or cognate processes) are used due to their high efficiency. As a pre-step, the production of semi-finished parts was the subject of accorded research work at the LUF. Therefore, a friction-based hot extrusion process was used for the full recycling or rework of aluminum chips into profiles. Investigations of the recycled semi-finished products show that they are comparable to conventionally produced semi-finished products in terms of dimensional stability and shape accuracy. An analysis of the mechanical properties of hardness and tensile strength shows that a final product with good and homogeneously distributed properties can be produced. Furthermore, significant correlations to the friction spinning process could be found that are useful for the above-mentioned direct part production from secondary aluminum.

Newest Developments on the Manufacture of Helical Profiles by Hot Extrusion

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Nooman Ben Khalifa ◽  
A. Erman Tekkaya
Keyword(s):  
Material Flow ◽  
Twist Angle ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Die Design ◽  
3D Fem ◽  
Extrusion Dies ◽  
Application Fields ◽  
Twisting Angle ◽  
Screw Rotors

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.

Application of Appropriate Coatings on Extrusion Dies and Evaluation of Their Performance During Hot Extrusion of Aluminum

2010 ◽  
Author(s):  
Antonios Lontos ◽  
George Demosthenous ◽  
Filippos Soukatzidis
Keyword(s):  
Hot Extrusion ◽  
Experimental Tests ◽  
Working Life ◽  
Element Model ◽  
Extrusion Process ◽  
Extrusion Speed ◽  
Coating Materials ◽  
Extrusion Dies ◽  
Billet Material ◽  
Aluminum Material

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.

MUSTANG-LC

Alloy Digest ◽  
1967 ◽  
Vol 16 (4) ◽  
Keyword(s):  
Physical Properties ◽  
High Speed ◽  
High Speed Steel ◽  
Hot Extrusion ◽  
Heat Treating ◽  
Hot Forming ◽  
Steel Company ◽  
Extrusion Dies ◽  
Die Life

Abstract Mustang-LC is a tungsten-molybdenum high-speed steel specially developed for hot work applications requiring long die life. It is recommended for hot forming and swaging dies, hot extrusion dies, hot punches, etc. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-192. Producer or source: Jessop Steel Company.

UNS T20819

Alloy Digest ◽  
1989 ◽  
Vol 38 (2) ◽  
Keyword(s):  
Elevated Temperatures ◽  
Hot Extrusion ◽  
Heat Treating ◽  
High Toughness ◽  
Extrusion Dies ◽  
Extrusion Die ◽  
Steel Mills ◽  
Temperature Performance ◽  
Heat Checking ◽  
Resistance To Heat

Abstract UNS T20819 is a hot-work tool and die steel that is characterized by excellent resistance to shock and abrasion at elevated temperatures. This steel provides relatively high toughness and outstanding resistance to heat checking and softening at elevated temperatures. Among its many applications are hot-punch tools, forging dies and inserts, brass extrusion dies, permanent molds for brass casting and hot-extrusion die inserts for steel. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-496. Producer or source: Tool steel mills.

scholarly journals Experimental Investigation and Comparison of the Thermal Performance of Additively and Conventionally Manufactured Heat Exchangers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 574
Author(s):  
Ana Vafadar ◽  
Ferdinando Guzzomi ◽  
Kevin Hayward
Keyword(s):  
Surface Roughness ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Experimental Studies ◽  
Manufacturing Method ◽  
Industrial Sectors

Air heat exchangers (HXs) are applicable in many industrial sectors because they offer a simple, reliable, and cost-effective cooling system. Additive manufacturing (AM) systems have significant potential in the construction of high-efficiency, lightweight HXs; however, HXs still mainly rely on conventional manufacturing (CM) systems such as milling, and brazing. This is due to the fact that little is known regarding the effects of AM on the performance of AM fabricated HXs. In this research, three air HXs comprising of a single fin fabricated from stainless steel 316 L using AM and CM methods—i.e., the HXs were fabricated by both direct metal printing and milling. To evaluate the fabricated HXs, microstructure images of the HXs were investigated, and the surface roughness of the samples was measured. Furthermore, an experimental test rig was designed and manufactured to conduct the experimental studies, and the thermal performance was investigated using four characteristics: heat transfer coefficient, Nusselt number, thermal fluid dynamic performance, and friction factor. The results showed that the manufacturing method has a considerable effect on the HX thermal performance. Furthermore, the surface roughness and distribution, and quantity of internal voids, which might be created during and after the printing process, affect the performance of HXs.

Analysis and optimization of hot extrusion process on strenx steel 900

2021 ◽  
Author(s):  
A. Damodar Reddy ◽  
P.N. Karthikeyan ◽  
S. Krishnaraj ◽  
Adarsh Ajayan ◽  
K. Sunil Kumar Reddy ◽  
...  
Keyword(s):  
Hot Extrusion ◽  
Extrusion Process

scholarly journals Measuring the Deformation of a Flat Die by Applying a Laser Beam on a Reflecting Surface

2009 ◽  
Vol 424 ◽  
pp. 197-204 ◽  
Author(s):  
W. Assaad ◽  
H.J.M. Geijselaers ◽  
K.E. Nilsen
Keyword(s):  
Finite Element ◽  
Laser Beam ◽  
Extrusion Process ◽  
Trial And Error ◽  
Element Calculation ◽  
Extrusion Dies ◽  
Cheap Method ◽  
Trial And Error Method ◽  
Reflecting Surface ◽  
Error Method

The design of extrusion dies depends on the experience of the designer. After the die has been manufactured, it is tested during an extrusion process and machined several times until it works properly. The die is designed by a trial and error method which is expensive interms of time consumption and the amount of scrap. Research is going on to replace the trial pressing with finite element simulations that concentrate on material and tool analysis. In order to validate the tool simulations, an experiment is required for measuring the deformation of the die. Measuring the deformation of the die is faced with two main obstacles: high temperature and little free space. To overcome these obstacles a method is tried, which works by applying a laser beam on a reflecting surface. This cheap method is simple, robust and gives good results. This paper describes measuring the deformation of a flat die used to extrude a single U shape profile. In addition, finite element calculation of the die is performed. Finally, a comparison is performed between experimental and numerical results.

Extrusion Simulation and Texture Study on Mg-Y Alloy

2015 ◽  
Vol 817 ◽  
pp. 531-537 ◽  
Author(s):  
Tao Tang ◽  
Yi Chuan Shao ◽  
Da Yong Li ◽  
Ying Hong Peng
Keyword(s):  
Steady State ◽  
Texture Evolution ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Deformation Texture ◽  
Arbitrary Lagrangian Eulerian ◽  
Fe Method ◽  
Tracer Particles ◽  
Numerical Simulation Methods ◽  
Crystal Plasticity Theory

In order to study the influence of extrusion process on texture development of alloys, numerical simulation methods were used to simulate the round and shape extrusion process and deformation texture. Extrusion of Mg-Y magnesium alloy was carried out at the temperature of 673K with different ram speeds to verify the simulation results. Instead of using the Lagrangian FE method, the Arbitrary Lagrangian-Eulerian (ALE) method was employed in this study so that a more accurate description of the steady-state extrusion process can be achieved. By obtaining strain histories of specified material tracer particles, the coupling of deformation and crystal plasticity theory was applied to simulate the texture evolution in hot extrusion. The results showed that the texture simulation corresponded well with the experimental ones. The study proposes a method to analyze the steady-state extrusion process and texture evolution, and can be used as a useful tool in optimizing the extrusion process.

scholarly journals Analysis and optimization of cooling channels performances for industrial extrusion dies

2021 ◽  
Author(s):  
Riccardo Pelacci ◽  
Marco Negozio ◽  
Barbara Reggiani ◽  
Lorenzo Donati ◽  
Luca Tomesani
Keyword(s):  
Liquid Nitrogen ◽  
Numerical Models ◽  
Extrusion Process ◽  
Die Design ◽  
Design Stage ◽  
Fe Model ◽  
Cooling Efficiency ◽  
Channel Design ◽  
Liquid Nitrogen Cooling ◽  
Experimental Trials

Liquid nitrogen cooling is widely used in the extrusion industrial practice in order to increase the production rate, to reduce the die temperature and to avoid defects on the profile exit surfaces resulting from an excessive heating. However, the efficiency of the cooling is deeply affected by position and design of the liquid nitrogen channel so that numerical modelling is gaining an increasing industrial interest in relation to the possibility offered to optimize the channel design without expensive and time-consuming experimental trials. In this work, a numerical FE model developed within COMSOL Multiphysics® is proposed and validated against experimental trials performed in industrial environment. The model combines the 3D simulation of the extrusion process with a 1D model of the cooling channel thus allowing the testing of a number of different solutions at the die design stage. The global aim of this work is the assessment of the liquid nitrogen cooling efficiency in the extrusion of an industrial aluminum profile and the proof of the potentials offered by numerical models to get an optimized channel design in terms of cooling efficiency, die thermal balancing and reduction of liquid nitrogen consumption.

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