scholarly journals Numerical simulation of rheological behavior of polymer in three layer co-extrusion process

AIP Advances ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 075221
Author(s):  
Chao Wang ◽  
Min Lei
2013 ◽  
Vol 554-557 ◽  
pp. 630-637 ◽  
Author(s):  
Martin Grüner ◽  
Marion Merklein

Aluminium alloys show a great potential for lightweight constructions due to their high strength and low density but the production of this material is very energy consuming. Also the recycling of aluminium alloys, e.g. chips from the milling process, shows different challenges. Beside contamination by cooling lubricant and oxidation of the surface of the chips the melting and rolling process for new semi finish products needs a high amount of energy. TEKKAYA shows a new approach for recycling of aluminium alloy chips by an extrusion process at elevated temperatures producing different kinds of profiles. A new idea is the production of components directly out of chips using severe plastic deformation for joining of the chips similar to the accumulative roll bonding process in sheet metal forming. In a first approach aluminium alloy chips out of a milling process were uniaxial compressed with different loads inside an axisymmetric tool installed in a universal testing machine. The compressed chip disks subsequently were tested with two experiments to gain information on their stability. First experiment is a disk compression test with the disk standing on its cylindrical surface, giving information on the stability perpendicular to the compression direction. Second experiment is a stacked disk compression test with three disks to investigate the stability parallel to compression direction. During all three tests force and displacement values are recorded by the universal testing machine. These data are also processed to calculate or identify input parameters for the numerical investigations. For numerical simulation ABAQUS in conjunction with the Drucker-Prager-Cap material model, which is often used for sintering processes, seems to be a good choice. By numerical simulation of the experiments and comparison with the experiments input parameters for the material model can be identified showing good accordance. This material model will be used in future numerical investigations of an extrusion process to identify tool geometries leading to high strains inside the material and by this to an increased stability of the parts.


2014 ◽  
Vol 36 (4) ◽  
pp. 630-634 ◽  
Author(s):  
Quan Wang ◽  
Bin Liu ◽  
Chaohua Huang ◽  
Xiao Sun

2018 ◽  
Vol 253 ◽  
pp. 17-26 ◽  
Author(s):  
H. Zhang ◽  
X. Li ◽  
X. Deng ◽  
A.P. Reynolds ◽  
M.A. Sutton

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3960
Author(s):  
Hong-Ling Hou ◽  
Guang-Peng Zhang ◽  
Chen Xin ◽  
Yong-Qiang Zhao

In the internal thread extrusion forming, if the process parameters are not selected properly, the extrusion torque will increase, the extrusion temperature will be too high, or even the tap will break. In order to obtain effective process parameters under certain working conditions, this paper uses a combination of numerical simulation and process experiment to analyze the influence of the bottom hole diameter, extrusion speed, and friction factor on the extrusion torque and extrusion temperature. Through an orthogonal experiment, the significant influence law of different process parameters on the extrusion torque and extrusion temperature was studied, and the order of their influence was determined. Based on the optimal process parameters, numerical simulations and process tests were carried out, and the extrusion effect and related parameters were compared and analyzed. The results show that the extruded thread has clear contour, uniform tooth pitch, complete tooth shape, and good flatness. Compared with before optimization, the maximum extrusion torque has been reduced by 37.15%, the maximum temperature has been reduced by 29.72%, and the extrusion quality has been improved. It shows that the optimized method and optimized process parameters have good engineering practicability.


2012 ◽  
Vol 446-449 ◽  
pp. 3803-3809
Author(s):  
Hooman Hoornahad ◽  
Eduard A. B. Koenders

The common approach to describe the rheological behavior of a granular-paste material relies on a description of the motion within the frame of continuum mechanics. However, since a granular-paste system cannot be considered as a homogeneous continuous fluid its behavior should not be estimated by common fluid models, such as Bingham or Herschell Bulkley models. Therefore, a continuum approach is not considered the best option to study the phase effects of a multi-phase material and its corresponding rheological behavior. In this particular case analytical techniques based on the multi-phase models are required. A more appropriate approach is to consider a granular-paste material as a two phase model that accounts for the effect of the gradually decreasing the volume fraction of the pasty phase until getting to zero value on the rheological behavior of the material. In this investigation, a cone test is used to evaluate the rheological behavior of a granular mix where a discrete element method (DEM) is considered as a basis of the numerical simulation.


2012 ◽  
Vol 626 ◽  
pp. 381-385
Author(s):  
Bao Hong Zhang ◽  
Yao Jin Wu ◽  
Zhi Min Zhang

This paper presents a case study of optimizing the forming process for a fan-shaped shell component. Numerical simulation was used to study the backward extrusion process of a fan-shaped shell. The underfill defect produced at the opening of the extruded shell due to the billet shape was solved and the minimal base thickness required to avoid the presence of the underfill defect at the bottom corner of the component was defined through the numerical simulation. The extrusion drawing and forming process of the fan-shaped shell were designed on the basis of the results of the numerical simulation. Forming experiments had been performed on the fan-shaped shell at 380 °C and cracking was found on the outside wall in the center of the extruded shell. Choked groove on the inner wall of the die and reducing the lubrication had been used to avoid the presence of cracking. The fan-shaped shell of AZ31 magnesium alloy has been successfully formed by the three-stage forming process of hot upsetting, hot backward extrusion and cold sizing.


Sign in / Sign up

Export Citation Format

Share Document