Physically Based Microstructure Modelling of AA6082 during Hot Extrusion

2009 ◽  
Vol 424 ◽  
pp. 27-34 ◽  
Author(s):  
Friedrich Krumphals ◽  
Pavel Sherstnev ◽  
Stefan Mitsche ◽  
S. Randjelovic ◽  
Christof Sommitsch
Keyword(s):  
Hot Extrusion ◽  
Extrusion Process ◽  
Process Conditions ◽  
Nucleation Sites ◽  
Key Points ◽  
Physically Based ◽  
Finite Element Package ◽  
Microstructure Model ◽  
Aluminium Extrusion ◽  
Extrusion Technology

Process parameters in aluminium extrusion technology are key points that influence product properties. The precipitation hardening aluminium alloy 6082 is investigated according to different process conditions and the influence onto the final microstructure is simulated as well as experimentally verified. A physical microstructure model based on three dislocation types and three nucleation sites for recrystallization is implemented into the commercial Finite Element package FORGE 2008 to calculate both the microstructure evolution during the extrusion process as well as the recrystallized fraction after the process. The precipitation kinetics during homogenization was investigated using the thermodynamic calculation software MatCalc since the main nucleation mechanism for recrystallization is particle stimulated. The experimental validation was done by miniature extrusion tests and the microstructure was investigated metallographically and by EBSD measurements.

Experimental Study of Hot Extrusion Micro Gear of Brass H62

2011 ◽  
Vol 189-193 ◽  
pp. 2903-2906
Author(s):  
Xu Dong Zhou ◽  
Xiang Ru Liu
Keyword(s):  
Dimensional Accuracy ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Plastic Behavior ◽  
Die Materials ◽  
Super Plastic ◽  
3D Fea ◽  
Die Set ◽  
Fea Simulation ◽  
Extrusion Technology

A new micro-forming method, combining a metal’s super-plastic behavior with hot extrudsion technology, has been developed for manufacturing micro-gear from brass H62. The micro-gear, which modulus m = 0.125mm, pressure angle α = 20°, number of teeth z = 6, tip diameter d = 1mm, was selected and its dies were designed with a better die approach angle based on the DEFORM-3D FEA simulation results of the hot extrusion process. Finally the micro-gear was successfully hot extruded at 650°C from blank Φ3mm×3mm with extrusion ratio about 17. A good dimensional accuracy for micro-gear was obtained by using this hot extrusion technology. In the special die set, the split die structure was designed, and the special die materials were chosen, such as the pressure ram was made of tungsten carbide, and the other dies were made of mold materials 4Cr5MoSiV1.

Simulation Study on Influence of Forming Process Parameters on Backward Extrusion Height of 6061 Aluminum-Alloy Wheel

2011 ◽  
Vol 121-126 ◽  
pp. 363-366
Author(s):  
Lu Li ◽  
Fang Wang
Keyword(s):  
Aluminum Alloy ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Forming Process ◽  
6061 Aluminum Alloy ◽  
Backward Extrusion ◽  
Punch Speed ◽  
Alloy Wheel ◽  
Forming Temperature ◽  
Extrusion Technology

Backward extrusion process of aluminum-alloy wheel forging is analyzed by the finite element method. The influence of punch speed and forming temperature on the backward extrusion height of 6061 aluminum alloy wheel is discussed. Studies show that the backward extrusion height increases with increasing forming temperature, and with decreasing punch speed at the same deformation load. It is indicated that when the ranges of forming temperature is from 450 to 500°C and the punch speed is 0.5-1 mm/s, the aluminum alloy wheel has the optimal forming quality. The analysis and conclusions in this paper are helpful in developing the hot extrusion technology specification of 6061 aluminum alloy.

Investigation and Comparison of Heat Transfers Analysis Used in Commercial FEM for Metal Forming

2013 ◽  
Vol 773-774 ◽  
pp. 176-185
Author(s):  
Isaac Flitta ◽  
Thomas Hatzenbichler ◽  
Bruno Buchmayr
Keyword(s):  
Heat Transfer ◽  
Fem Simulation ◽  
Tool Material ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Material Interface ◽  
Transfer Parameter ◽  
Aluminium Extrusion ◽  
Definition Of ◽  
Heat Transfer Parameter

During an Aluminium extrusion process, the extrusion parameters, i.e. friction, heat transfer, etc. are significantly influence by the temperature gradients produced in the billet during transfer to the container and after upsetting the container. The heat transfer at the tool/billet interface governs the temperature profile throughout the billet and tools during extrusion and consequently has a critical influence on the results. Although FEM technique offers great potential, care must be taken when applying the analysis to the hot extrusion of rate sensitive alloys. The most useful approach of an FEM simulation would thus be to include both the tooling and the billet in the calculation as discretised meshes. Because of the occurrence of the conductive and convective heat transfer, the deformation during hot extrusion is not adiabatic and estimation of the temperature increase is alloy dependent. The aim of this paper is to investigate and to compare how commercial FEM codes assign and deal with the heat transfer parameter at the tool/material interface. Three commercial FEM codes were investigated and compared; Simufact, Deform and Forge. The usefulness and limitation when using commercial FEM codes are discussed. Methods to assess difficulty of comparison are presented. The work illustrates the essentials of numerical analysis in the comprehension of the thermo-mechanical events occurring during large deformation. Results are presented for velocity distribution and temperature evolution in both materials and tools. It is shown that the heat transfer parameter to be extremely sensitive when attempting to simulate the hot deformation. Moreover, the accuracy of the results does not only depended on the geometric definition of the tooling and material data but also the governing boundary conditions between the material and tooling.

A TEM study of the effect of oxygen on nanocavity formation and precipitation in rapid - solidified Fe-16Ni-9Cr stainless steels

1994 ◽  
Vol 52 ◽  
pp. 700-701
Author(s):  
S. Wisutmethangoon ◽  
T. F. Kelly ◽  
J.E. Flinn
Keyword(s):  
Stainless Steels ◽  
High Mobility ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Gas Atomization ◽  
Cavity Formation ◽  
Nucleation Sites ◽  
Heat Treated ◽  
Different Types ◽  
Effect Of Oxygen

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

THE CHARACTERISTICS OF ARTIFICIAL RICE WITH SEAWEED Eucheuma cottonii ADDITION AS A DIETARY FIBER SOURCE

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Natalia Prodiana Setiawati ◽  
Joko Santoso ◽  
Sri Purwaningsih
Keyword(s):  
Blood Glucose ◽  
Dietary Fiber ◽  
Dietary Fibre ◽  
Extrusion Process ◽  
The Body ◽  
Starch Digestibility ◽  
Food Commodities ◽  
The Stability ◽  
Extrusion Technology ◽  
Eucheuma Cottonii

The utilization of local food commodities such as corn and cassava with seaweed addition as a dietary fiber source for producing artificial rice through extrusion technology is an  alternative for food diversification. The research was carried out to find out the best composition (rice, corn, cassava, and seaweed) and temperature of extrusion process on making artificial rice and the influence of dietary fibre on sensory properties and physicochemical. The composition of rice, corn, and cassava in proportion  of 1:3:1 with 20% seaweed, Eucheuma cottonii, addition and temperature extruder of 90 °C were selected as the best product for artificial rice. The  sensory evaluation was 8.02±0.21 (people’s preference). In physicochemical properties, dietary fiber significantly affected on low bulk density and starch digestibility. This condition is very good for health especially in maintaining the stability of blood glucose in the body. Keywords: artificial rice, composition, extrusion, seaweed, dietary fibre, temperature

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 Rheological Basics for Modeling of Extrusion Process of Wood Polymer Composites

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 622
Author(s):  
Krzysztof Wilczyński ◽  
Kamila Buziak ◽  
Adrian Lewandowski ◽  
Andrzej Nastaj ◽  
Krzysztof J. Wilczyński
Keyword(s):  
Polymer Composites ◽  
Process Modeling ◽  
Slip Flow ◽  
Extrusion Process ◽  
Process Conditions ◽  
Rheological Models ◽  
Wood Polymer ◽  
Slip Effects ◽  
Process Simulations ◽  
Wood Polymer Composites

Wood polymer composites are materials with pseudoplastic and viscoelastic properties. They have yield stress and exhibit slip during flow. Studies on extrusion and rheology, as well as on process modeling of these highly filled materials are limited. Extensive rheological and extrusion modeling studies on the wood polymer composite based on the polypropylene matrix were performed. Viscous and slip flow properties were determined (with Rabinowitsch, Bagley, and Mooney corrections) at broad (extrusion) range of shear rate and temperature, using a high-pressure capillary rheometer. Rheological models of Klein and power-law were used for flow modeling, and Navier model was applied for slip modeling. A novel global computer model of WPC extrusion with slip effects has been developed, and process simulations were performed to compute the extrusion parameters (throughput, power consumption, pressure, temperature, etc.), and to study the effect of the material rheological characteristics on the process flow. Simulations were validated experimentally, and were discussed with respect to both rheological and process modeling aspects. It was concluded that the location of the operating point of extrusion process, which defines the thermo-mechanical process conditions, is fundamentally dependent on the rheological materials characteristics, including slip effects.

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.

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.

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