Tool Design Induced Anisotropic Flow Behavior of Hot Extruded Aluminum Profiles

2013 ◽  
Vol 585 ◽  
pp. 131-138
Author(s):  
Stefan Ossenkemper ◽  
Matthias Haase ◽  
Celal Soyarslan ◽  
Andreas Jäger ◽  
A. Erman Tekkaya
Keyword(s):  
Flow Behavior ◽  
Extrusion Direction ◽  
Hot Extrusion ◽  
Longitudinal Direction ◽  
Extrusion Process ◽  
Tool Design ◽  
Compression Tests ◽  
Lateral Direction ◽  
Plane Anisotropy ◽  
Aluminum Profiles

The hot extrusion process may lead to frequently observed textures in the profiles, like fiber structures in longitudinal direction. Aluminum profiles (AA6060) were extruded with different tool types (flat-face dies and modified porthole dies). Compression tests of cylindrical specimens, which were machined out of these profiles likewise in extrusion direction, were conducted to examine possible effects of the in-plane anisotropy in lateral direction. A hardness distribution over the cross section of the specimens was measured. It was found that dependent on tool design and profile geometry, the specimens developed preferred lateral flow directions during upsetting. Simulations of the upsetting test, with assigned Hill parameters to consider anisotropy of the material, showed, that this anisotropy, not the local hardness nonuniformity, is the main reason for the detected plastic flow properties.

Effects of Microstructure and Texture on the Mechanical Properties of Extruded Mg−Gd−Nd−Y−Zn Alloy

2012 ◽  
Vol 509 ◽  
pp. 68-74
Author(s):  
Xiu Li Hou ◽  
Xu Sun ◽  
Li Min Wang ◽  
Zhan Yi Cao
Keyword(s):  
Mechanical Properties ◽  
Extrusion Direction ◽  
Aging Treatment ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Fiber Texture ◽  
Alloy Sheet ◽  
Mechanical Anisotropy ◽  
Aged Alloy ◽  
Zn Alloy

In present work, the Mg−Gd−Nd−Y−Zn alloy sheets were prepared by hot extrusion technique. The microstructure, texture and mechanical properties of the extruded alloy were investigated. After hot extrusion, the alloy reveals a greatly refined microstructure due to the dynamic recrystallization. The coarse eutectic phases were crushed into small particles during extrusion process, which brings a promotion of grain refinement. A weak basal fiber texture was obtained in the as-extruded alloy owing to the influence of RE (rare earth) alloying elements. The as-extruded alloy exhibits mechanical anisotropy that the strengths and elongations in the extrusion direction are both higher than those in the transverse direction. And this behavior does not change with increasing temperature. It results from the weak texture and the distribution of eutectic phase particles in the alloy sheet. Through isothermal aging treatment, significant strengthening is achieved in the peak-aged alloy, and the mechanical anisotropy still exists.

Fabrication of Aluminum/Aluminum Nitride Composites by Reactive Mechanical Alloying

2007 ◽  
Vol 534-536 ◽  
pp. 181-184
Author(s):  
Seung Hoon Yu ◽  
Kwang Seon Shin
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Elevated Temperatures ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Processing Technique ◽  
Compression Tests ◽  
Composite Powders ◽  
Al Matrix Composites

Various reactions and the in-situ formation of new phases can occur during the mechanical alloying process. In the present study, Al powders were strengthened by AlN, using the in-situ processing technique during mechanical alloying. Differential thermal analysis and X-ray diffraction studies were carried out in order to examine the formation behavior of AlN. It was found that the precursors of AlN were formed in the Al powders and transformed to AlN at temperatures above 600oC. The hot extrusion process was utilized to consolidate the composite powders. The composite powders were canned in an Al can and then extruded at elevated temperatures. The microstructure of the extrusions was examined by SEM and TEM. In order to investigate the mechanical properties of the extrusions, compression tests and hardness measurements were carried out. It was found that the mechanical properties and the thermal stability of the Al/AlN composites were significantly greater than those of conventional Al matrix composites.

Simulation of the Grain Structure Evolution of a Mg-Al-Ca-Based Alloy during Hot Extrusion Using the Cellular Automation Method

2011 ◽  
Vol 491 ◽  
pp. 265-272 ◽  
Author(s):  
L. Li ◽  
F. He ◽  
X. Liu ◽  
Yan Lou ◽  
Jie Zhou ◽  
...  
Keyword(s):  
Hot Extrusion ◽  
Extrusion Process ◽  
Grain Structure ◽  
Structure Evolution ◽  
Compression Tests ◽  
3D Fem ◽  
Parameter Recovery ◽  
Cellular Automation ◽  
Average Grain Size ◽  
Ram Speed

In the present study, the evolution of the grain structure of a Mg-Al-Ca-based alloy during hot extrusion was simulated with the cellular automation method. The Laasraoui-Jonas microstructure model was used to describe the dislocation evolution inside crystallites during dynamic recrystallization. The parameters in the Laasraoui-Jonas model, such as the hardening parameter, recovery parameter and material constants, were determined from the flow stress-strain data obtained from hot compression tests using a Gleeble-1500 thermomechanical simulator. The extrusion process was simulated using a DEFORM 3D FEM code. The influence of ram speed on grain structure evolution was analyzed. It was found that the average grain size increases with increasing ram speed. Good agreements between the predicted and observed grain structures were achieved.

In-Situ Solid-State Synthesis of Mg Composite with Mg2Si Dispersoids

2005 ◽  
Vol 475-479 ◽  
pp. 497-500
Author(s):  
Ritsuko Tsuzuki ◽  
Katsuyoshi Kondoh
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
High Performance ◽  
Extrusion Direction ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Synthesis Temperature ◽  
Solid State Synthesis ◽  
Casting Alloys

Super light and high performance Mg2Si/Mg composites, which had excellent mechanical properties, were developed via the combination of solid-state synthesis and hot extrusion process. In this study, cold compacting (CP) and repeated plastic working (RPW) were firstly carried out for the mixture of Mg-Si powders, and the refinement of both Mg grains and dispersoids. Each specimen was evaluated by observation of microstructure and tensile test. As a result, it was understood that Mg2Si dispersoids were refined and dispersed into Mg matrix, and were flowed along extrusion direction. And their mechanical properties were higher than the conventional die casting alloys. Also the effect of RPW as the improvement of properties and the decrease of synthesis temperature were confirmed.

Finite Volume Simulation in Porthole Dies Extrusion of Aluminum Profiles

2011 ◽  
Vol 291-294 ◽  
pp. 290-296
Author(s):  
Lei Cheng ◽  
Shui Sheng Xie ◽  
You Feng He ◽  
Guo Jie Huang ◽  
Yao Fu
Keyword(s):  
Numerical Simulation ◽  
Finite Volume ◽  
Cross Section ◽  
Process Analysis ◽  
Flow Behavior ◽  
Metal Flow ◽  
Extrusion Process ◽  
Porthole Die ◽  
Simulation Results ◽  
Aluminum Profiles

FEM simulation of aluminum profiles in porthole die extrusion process using Lagrange mesh description will inevitably bring mesh self-contact, severe grid distortion and frequent remeshing, which will result in the loss of computational accuracy and excessive calculation time. In order to solve the above mentioned problems, numerical simulation of aluminum profiles with large and complicated cross-section in extrusion process was achieved using finite volume method based on Euler mesh description. The metal flow behavior and welding course was investigated in detail, which can provide the theoretical guide for porthole die design and optimization. In addition, extrusion experiment was carried out by numerical simulation results. The experimental extrudate was in good agreement with the simulation results, which laid a good solid foundation for non-steady state extrusion process analysis of large scale and complicated cross-section profiles.

Analyses of Plastic Flow and Die Design during Hot Extrusion of Magnesium Alloy Strips

2010 ◽  
Vol 443 ◽  
pp. 98-103 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Shih Ming Tu
Keyword(s):  
Magnesium Alloy ◽  
Plastic Flow ◽  
Thickness Distribution ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Die Design ◽  
Thin Strip ◽  
Compression Tests ◽  
Ram Speed ◽  
Product Thickness

This study involves analyses and experiments of hot extrusion of magnesium alloy strips. Hot compression tests were firstly conducted to obtain the magnesium alloy’s plastic flow stresses at high temperatures. These data are used in the finite element simulations of the thin strip extrusion process. Using the FE simulations, the flow pattern of the magnesium alloy billet within the die, the temperature variation and the thickness distribution at the die exit were analyzed. The effects of different die bearing height design, initial billet temperatures and ram speed on the extrusion load, the temperature at the die exit and the product thickness distribution were also discussed. Finally, hot extrusion experiments were conducted and the experimental values of the extrusion load and dimensions of the products were compared with the analytical values to validate the analytical model. Sound products were obtained using the best designed bearing heights and other appropriate extrusion conditions.

scholarly journals A Characterization for the Deformation Behavior of As-Cast P91 Alloy Steel and Utilization in Hot Extrusion Process

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Lu Jia ◽  
Yongtang Li ◽  
Yang Zhang
Keyword(s):  
Numerical Simulation ◽  
Alloy Steel ◽  
Deformation Behavior ◽  
Constitutive Models ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Compression Tests ◽  
Thermal Compression ◽  
Wide Range ◽  
Gleeble 3500

The constitutive models of as-cast P91 alloy steel were investigated by unidirectional thermal compression tests, which were conducted over a wide range of temperature and strain rate on Gleeble-3500 thermal simulation machine. The constitutive models were coupled with finite element method to simulate the hot extrusion process. Furthermore, the industrial hot extrusion experiment on actual pipe was conducted on 500 MN vertical extrusion machine and the load-displacement data during the extrusion were recorded. Comparisons between the numerical simulation and industrial experimental results were carried out and confirmed that the developed constitutive models can be used in the simulation and industrial research of compact hot extrusion process.

scholarly journals Simulation and Experiment of Manufacturing Process for Structural Aluminum Parts with Hard to Plastic Forming

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 207
Author(s):  
Chul Jin
Keyword(s):  
Extrusion Direction ◽  
Hot Extrusion ◽  
Maximum Load ◽  
Extrusion Process ◽  
Cylindrical Part ◽  
Forging Process ◽  
Plastic Forming ◽  
Forming Analysis ◽  
Simulation And Experiment ◽  
Warm Forging

A process comprising a hot extrusion process and a warm forging process was designed to form an umbrella-shaped aluminum structural component with a high degree of difficulty for the plastic forming method. A circular cylindrical part was extruded with a hot extrusion process, and then an embossing part was produced with a warm forging process. The formability and the maximum load required for forming were then determined using a forming analysis program. The hot extrusion process was executed at 450 °C under the extrusion speed at 6 mm/s, while the warm forging process was executed at 260 °C under the forging speed at 150 mm/s. The simulation results showed that the load required for hot extrusion was 1019 ton, while the load required for the warm forging was 534 ton. The umbrella-shaped part was manufactured by using a 1600 ton capacity press. The graphite lubricant was coated on the mold as well as the material. A forming experiment was performed under the same condition with the simulation condition. The portion where extrusion was done became elliptical with the α-Al phase elongated towards extrusion direction. Whereas, the α-Al phase became circular in the forged portion. The tensile strength value was found as 345 MPa, while elongation rate was 12%. Meanwhile, Vickers hardness value at the extruded portion was 105 HV, and it was 110 HV at the forged portion.

Microstructure and Mechanical Properties of As-Cast and As-Extruded Mg-Gd-Er-Zn-Zr Alloy

2015 ◽  
Vol 1088 ◽  
pp. 221-226 ◽  
Author(s):  
Kai Wen ◽  
Wen Bo Du ◽  
Ke Liu ◽  
Zhao Hui Wang ◽  
Shu Bo Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Room Temperature ◽  
Cast Alloy ◽  
Extrusion Direction ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Microstructure And Mechanical Properties ◽  
Room Temperature Tensile Test ◽  
Zr Alloy

The Microstructure and mechanical properties of as-cast and as-extruded Mg-12Gd-2Er-1Zn-0.6Zr alloy are investigated in the present paper. The microstructure is analyzed by OM, SEM and TEM with SAED, and the mechanical properties are valued by the room temperature tensile test. The result shows that the coarse Mg5(Gd, Er, Zn) phase in the as-cast alloy was broken during hot extrusion process, and it was distributed at the grain boundary along the extrusion direction. The enhancement in mechanical properties of the extruded alloy is mainly ascribed to the refinement of these grains. The sizes of dynamical recrystallized grains are homogeneously, which was about 7 μm. Stacking fault existed in the as-cast alloy, which has a little effect on the dynamic recrystallization because of its tiny thicknesses.

Hot Deformation Behavior and Microstructure Evolution of GH625 Superalloy Tube during Extrusion Process

2011 ◽  
Vol 291-294 ◽  
pp. 640-644
Author(s):  
Qing Miao Guo ◽  
De Fu Li ◽  
Sheng Li Guo ◽  
Guo Ling Xie
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Flow Behavior ◽  
Outer Wall ◽  
Extrusion Process ◽  
Compression Tests ◽  
Hot Deformation Behavior

Flow behavior and microstructures of GH625 superalloy were investigated by hot compression tests. Then the GH625 superalloy tube was hot extruded according to the hot deformation behavior, and the microstructures of different position of extruded tube was also analyzed. The results show that the actual deformation temperature of the specimen deformed at a strain rate of 10.0s-1 is higher than the preset temperature, resulting in a deformation thermal effect. Thus, the microstructure evolution of GH625 superalloy is controlled both by the strain rate and deformation temperature. It is also found that the GH625 superalloy tube can be successfully fabricated with a stable extrusion speed of 40 mm·s-1, extrusion ratio of 4.1 and preheating temperature of 1200°C. The microstructure of extruded tube was obviously fined due to the occurrence of dynamic recrystallization(DRX). Different degrees of DRX were observed in outer wall, center and inner wall of the tube, which is similar to that in the head, middle and tail of the tube. An extruded tube containing fully DRX grains can be obtained by cutting the head and tail of the tube, and machining a small amount of the inner wall.

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