Equal Channel Angular Extrusion of AA 5083

2018 ◽  
Vol 1148 ◽  
pp. 82-87
Author(s):  
Varadala Ananda Babu ◽  
Gurugubelli Swami Naidu ◽  
B. Sateesh
Keyword(s):  
Cross Sections ◽  
Equal Channel Angular Extrusion ◽  
Dead Zone ◽  
Wear Behaviour ◽  
Ultrafine Grain ◽  
Dry Sliding Wear ◽  
Outer Corner ◽  
Angular Extrusion ◽  
Set Up ◽  
Number Of Passes

Equal Channel Angular Extrusion (ECAE) is used as a top down process to produce bulk nano/ultrafine grain structured materials by inducing high amount of strain with less experimental set up. In the present study AA 5083 alloy with circular and square cross sections are extruded at room temperature using two dies having cannels with circular and square cross sections respectively. Both the dies used in this study are having same channel angle (Φ)1200and outer corner angle (Ψ) 200. The circular and square billets are extruded for four times in route BC. The objective of this work is to study the effect of cross section of the billet, number of passes on grain refinement, mechanical properties and wear behaviour of AA 5083. Significant reduction in grain size is observed in extruded material using Field Emission Scanning Electron Microscope (FE-SEM) in the range of 80nm to 600nm after four passes. The microhardness in extruded materials is improved with no. of passes in both cross sectioned billets and it is more predominant for square billets even after two passes. The effect of dead zone is less in case of square billets and hence they have shown more structural homogeneity. The dry sliding wear tests are conducted to study the wear behaviour of the ECAEd materials. It is observed that the wear rate and coefficient of friction are reduced with number of passes in both the cases and rate of decrease is more in case of square billets.

Numerical Simulation of Al 6062 Alloy Deformation Behavior Using Equal Channel Angular Extrusion Process with Different Die Angles

2015 ◽  
Vol 813-814 ◽  
pp. 557-562
Author(s):  
Aitha Lavanya ◽  
Perumalla Janaki Ramulu ◽  
G. Sreekanth Kumar ◽  
P. Ramya Sree ◽  
Sirish Battacharya ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Metal Forming ◽  
Equal Channel Angular Extrusion ◽  
Frictional Coefficient ◽  
Maximum Load ◽  
Extrusion Process ◽  
Outer Corner ◽  
Cylindrical Billet ◽  
Angular Extrusion ◽  
Simulation Results

The equal channel angular extrusion (ECAE) is one of the most important methods used for bulk metal forming. In which die angles are the most importent parameter. This paper attempts to determine the effect of different die angles during ECAE process for 6062 aluminum alloy deformation. Numerical simulations are performed for ECAE process on cylindrical billet of 6062 aluminum alloy at a constant frictional coefficient (μ) of 0.08 and punch speed of 15 mm/sec. Die has made with inner corner angles of (φ) =105°, 115°, 125°and 135° by fixing the outer corner angle (ψ) of 6°, punch is designed with a radii (R) of 4.75mm and height of 50mm. From the simulation results, tha data has been obtained in the form of load stroke behavior, and energy consumend during the punch stoke. It is observed that the maximum load and more energy consumption during the process is noted for lower angle.

Microstructure and Mechanical Properties Resulting from Cold Rolling of Equal Channel Angular Extruded Commercial Purity Copper

2006 ◽  
Vol 503-504 ◽  
pp. 733-738
Author(s):  
A. Krishnaiah ◽  
Chakkingal Uday ◽  
P. Venugopal
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cold Rolling ◽  
Equal Channel Angular Extrusion ◽  
Pure Copper ◽  
Ultrafine Grain ◽  
Ultrafine Grain Size ◽  
Ultrafine Grained ◽  
Angular Extrusion ◽  
Initial Processing

Equal channel angular extrusion (ECAE) is a processing method for introducing an ultrafine grain size into a material. In the present study, a two-step severe plastic deformation process was used to produce ultrafine grained copper with significantly enhanced strength. Equal channel angular extrusion was first used to refine the grain size of copper samples. The copper samples were further processed by cold rolling (CR) to a strain of 0.67 (about 50% reduction). This two-step process produced ultrafine grained copper with strengths higher than those of pure copper processed through ECAE only. This paper reports the microstructures and mechanical properties of the copper specimens processed by a combination of room temperature ECAE and CR. The effectiveness of initial processing by ECAE prior to cold rolling is discussed.

Analysis of Cavity Tool Stresses in Channel Angular Extrusion

2007 ◽  
Vol 340-341 ◽  
pp. 1381-1386 ◽  
Author(s):  
R. Lupoi ◽  
F.H. Osman (1)
Keyword(s):  
Plastic Deformation ◽  
Cross Sections ◽  
Equal Channel Angular Extrusion ◽  
Solid Material ◽  
Internal Stresses ◽  
Deformation Model ◽  
Deformable Solid ◽  
Element Analysis ◽  
General Process ◽  
Angular Extrusion

The Channel Angular Extrusion (CAE) technique is a process, in which a deformable solid material is led to yielding through the intersection of inclined channels. Compared to classic plastic deformation, the process is technically simple but the material experiences, instantly, large plastic deformation. The deformation occurs locally and high internal stresses develop during the process. In most cases the process is used for grain size refinement. Equal Channel Angular Extrusion (ECAE) is a special case where the intersecting channels are of equal cross sections. In this paper, an analytical study of the internal stresses and those developed along CAE tools is presented. A deformation model is introduced for the general process of channel extrusion in which the intersecting channels are not necessarily equal. The procedure splits the material at the intersection of the channels into two zones; one causes the deformation while the other remains rigid. The analysis is also applied to the particular case of ECAE, and the results are compared with those obtained from a finite element analysis and the overall experimental pressure.

Improvement of Strength of Lotus-Type Porous Aluminum through ECAE Process

2011 ◽  
Vol 695 ◽  
pp. 263-266 ◽  
Author(s):  
Tae Bum Kim ◽  
Masakazu Tane ◽  
Shinsuke Suzuki ◽  
Takuya Ide ◽  
Hiroshi Utsunomiya ◽  
...  
Keyword(s):  
Large Deformation ◽  
Vickers Hardness ◽  
Equal Channel Angular Extrusion ◽  
Pore Morphology ◽  
Porous Aluminum ◽  
Cylindrical Pores ◽  
Angular Extrusion ◽  
Number Of Passes

Lotus-type porous aluminum with cylindrical pores oriented in one direction was deformed by Equal Channel Angular Extrusion (ECAE) through a 150° die with sequential 180° rotations, and the pore morphology and Vickers hardness after the extrusion were investigated. The Vickers hardness increases with increasing number of passes in the extrusions both parallel and perpendicular to the pore direction, accompanied by the decrease of porosity. The densification occurs more easily in the perpendicular extrusions than in the parallel extrusions, and the large deformation by the densification gives rise to the large increase in the Vickers hardness for the perpendicular extrusions.

Enhanced Ductility due to Grain Refinement by Equal Channel Angular Extrusion in Automotive Aluminium Alloy 6016

2006 ◽  
Vol 503-504 ◽  
pp. 657-662 ◽  
Author(s):  
P.W.J. McKenzie ◽  
Rimma Lapovok ◽  
Peter F. Thomson
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Aluminium Alloy ◽  
Equal Channel Angular Extrusion ◽  
Cold Water ◽  
Heat Treatment Condition ◽  
Engineering Strain ◽  
Average Grain Size ◽  
Angular Extrusion ◽  
Number Of Passes

Equal Channel Angular Extrusion (ECAE) with varying levels of applied backpressure was used to refine the microstructure of commercial automotive aluminium alloy 6016 at room temperature using route BC and a 90° die. Before processing, the alloy was solution heat treated at 560°C for 1 hour to produce an initial average grain size of ~190μm (in the furnace cooled condition) and ~200μm (in the water quenched condition). Two needle-like secondary phase precipitates were observed predominantly at grain boundaries and identified as α-Fe Al12Fe3Si2 and β-Fe Al5FeSi. The ability of Al 6016 to accumulate strain by simple shear was found to be dependent upon both the heat treatment condition and level of applied backpressure. The furnace cooled (FC) condition was found to accumulate higher strains than the cold water quenched (WQ) condition (under the same applied backpressure) with higher levels of backpressure allowing both conditions to accumulate greater equivalent plastic strains. A series of static annealing experiments were performed on as-processed material to investigate the grain stability of the ultrafine grained structure obtained after ECAE. Grain growth was observed to occur at 250°C in the FC condition of Al 6016 after 12 passes of ECAE where the average grain size approached 1μm. The engineering strain to failure in elevated temperature tensile testing was found to be dependent upon the number of passes of ECAE, test temperature, strain rate and level of applied backpressure. Increasing the number of passes and level of applied backpressure during ECAE and decreasing the strain rate during testing was found to produce the greatest tensile ductilities at 200°C (FC condition) and 300°C (WQ condition).

Finite Element Model of Equal Channel Angular Extrusion of Ultra High Molecular Weight Polyethylene

2021 ◽  
pp. 1-30
Author(s):  
Kostiantyn Vasylevskyi ◽  
Igor Tsukrov ◽  
Kateryna Miroshnichenko ◽  
Stanislav Buklovskyi ◽  
Hannah Grover ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Finite Element ◽  
Shear Strain ◽  
High Molecular Weight ◽  
Equal Channel Angular Extrusion ◽  
Dead Zone ◽  
Extrusion Force ◽  
Element Analysis ◽  
Angular Extrusion ◽  
Ultra High Molecular Weight

Abstract Ultra-high molecular weight polyethylene (UHMWPE) used in biomedical applications, e.g. as a bearing surface in total joint arthroplasty, has to possess superior tribological properties, high mechanical strength, and toughness. Recently, equal channel angular extrusion (ECAE) was proposed as a processing method to introduce large shear strains to achieve higher molecular entanglement and superior mechanical properties of this material. Finite element analysis (FEA) can be utilized to evaluate the influence of important manufacturing parameters such as the extrusion rate, temperature, geometry of the die, back pressure, and friction effects. In this paper we present efficient FEA models of ECAE for UHMWPE. Our studies demonstrate that the choice of the constitutive model is extremely important for the accuracy of numerical modeling predictions. Three considered material models (J2-plasticity, Bergstrom-Boyce, and the Three Network Model) predict different extrusion loads, deformed shapes and accumulated shear strain distributions. The work has also shown that the friction coefficient significantly influences the punch force and that the 2D plane strain assumption can become inaccurate in the presence of friction between the billet and the extrusion channel. Additionally, a sharp corner in the die can lead to the formation of the so-called “dead zone” due to a portion of the material lodging into the corner and separating from the billet. Our study shows that the presence of this material in the corner substantially affects the extrusion force and the resulting distribution of accumulated shear strain within the billet

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