Features of Twist Extrusion: Method, Structures & Material Properties

2006 ◽  
Vol 114 ◽  
pp. 69-78 ◽  
Author(s):  
Yan Beygelzimer ◽  
Dmitry Orlov ◽  
Alexander Korshunov ◽  
Sergey Synkov ◽  
Viktor Varyukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Equal Channel Angular Extrusion ◽  
High Pressure Torsion ◽  
Roll Bonding ◽  
Fine Grained ◽  
New Methods ◽  
Average Grain Size ◽  
Twist Extrusion ◽  
3D Deformation ◽  
Extrusion Method

During the last decade it has been shown that severe plastic deformation (SPD) is a very effective for obtaining ultra-fine grained (UFG) and nanostructured materials. The basic SPD methods are High Pressure Torsion (HPT) and Equal Channel Angular Extrusion (ECAE). Recently several new methods have been developed: 3D deformation, Accumulative Roll Bonding, Constrained Groove Pressing, Repetitive Corrugation and Straightening, Twist Extrusion (TE), etc. In this paper the twist extrusion method is analyzed in terms of SPD processing and the essential features from the “scientific” and “technological” viewpoint are compared with other SPD techniques. Results for commercial, 99.9 wt.% purity, copper processed by TE are reported to show the effectiveness of the method. UFG structure with an average grain size of ~0.3 μm was produced in Cu billets by TE processing. The mechanical properties in copper billets are near their saturation after two TE passes through a 60º die. Subsequent processing improves homogeneity and eliminates anisotropy. The homogeneity of strength for Cu after TE is lower than after ECAE by route BC, but higher than after ECAE by route C. The homogeneity in ductility characteristics was of almost of inverse character. The comparison of mechanical properties inhomogeneity in Cu after TE and ECAE suggests that alternate processing by ECAE and TE should give the most uniform properties.

Experimental and FEM Analysis of the AA 6082 Processed by Equal Channel Angular Extrusion

2011 ◽  
Vol 478 ◽  
pp. 46-53 ◽  
Author(s):  
Javier León ◽  
C.J. Luis-Pérez ◽  
Daniel Salcedo ◽  
Ivan Pérez ◽  
Juan Pablo Fuertes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Equal Channel Angular Extrusion ◽  
High Pressure Torsion ◽  
Fem Analysis ◽  
Fem Simulations ◽  
Roll Bonding ◽  
Angular Extrusion ◽  
Deformation Processes ◽  
Made In

Recent studies have shown that severe plastic deformation processes (SPD) improve the mechanical properties of the processed parts. Some of the most outstanding SPD processes are as follows: High Pressure Torsion (HPT), Repetitive Corrugation and Straightening (RCS), Cyclic Extrusion Compression (CEC), Accumulative Roll Bonding (ARB), Conform and Continuous Combined Drawing and Rolling (CCDR), among others, but the most well-known is Equal Channel Angular Extrusion or Pressure (ECAE/ECAP). The aim of these processes is to introduce high values of deformation inside the parts in order to reduce the grain size and thus to improve the mechanical properties of the starting material. The study of the damage imparted to an AA-6082 alloy is made in the present work. This alloy is received as cast and it is quenched at a temperature of 530 °C during 4 hours in order to be processed by ECAE at room temperature using different geometries of the dies. The imparted damage is also studied by using FEM simulations.

Effect of Intense Plastic Straining and Subsequent Heat Treatment on Mechanical Properties of an Al-Li-Mg-Sc-Zr Alloy

2010 ◽  
Vol 89-91 ◽  
pp. 389-394 ◽  
Author(s):  
Anna Mogucheva ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Equal Channel Angular Extrusion ◽  
Solution Treatment ◽  
Precipitation Sequence ◽  
Rectangular Shape ◽  
Fine Grained ◽  
Average Grain Size ◽  
Fine Grained Structure ◽  
Zr Alloy

An Al-5.1%Mg-2.1%Li-0.17%Sc-0.08%Zr (in mass%) alloy designated as 1421 Al was subjected to equal channel angular extrusion (ECAE) with rectangular shape of channels up to fixed true strains of ~4 and ~8 at a temperature of 325oC. This processing provided the formation of uniform recrystallized structures with micron scale average grain size. The 1421 Al after ECAE processing and in initial hot extruded condition was subjected to solution treatment followed by oil quenching and subsequent ageing. Fine grained structure evolved under ECAE remains essentially unchanged under solution treatment. However, this structure affects significantly the precipitation sequence during ageing. Relationships between microstructure and service mechanical properties are considered.

scholarly journals Influence of Steel Grain Size on Residual Stress in Grinding Processing

2010 ◽  
Vol 638-642 ◽  
pp. 2389-2394 ◽  
Author(s):  
Masahide Gotoh ◽  
Katsuhiro Seki ◽  
M. Shozu ◽  
Hajime Hirose ◽  
Toshihiko Sasaki
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Grain Size ◽  
Stress State ◽  
Mechanical Grinding ◽  
Fine Grained ◽  
Residual Stress State ◽  
Analysis Methods ◽  
Average Grain Size ◽  
Fine Grained Steels

The fine-grained rolling steels NFG600 and the conventional usual rolling steels SM490 were processed by sand paper polishing and mechanical grinding to compare the residual stress generated after processing. The average grain size of NFG600 and SM490 is 3 μm and 15μm respectively. Therefore improvement of mechanical properties for such fine-grained steels is expected, it is important to understand the residual stress state of new fine-grained materials with processing. In this study, multi axial stresses of two kinds of specimens after polishing and grinding were measured by three kinds of analysis methods including cos-ψ method. As a result, as for σ33, the stress of NFG was compression, though that of SM490 was tension.

Evolutions of Microstructure for Multilayered Al-Mg Alloy Composites by Accumulation Roll Bonding (ARB) Process

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao
Keyword(s):  
Multilayer Structure ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Fine Grained ◽  
Hardness Tester ◽  
Average Grain Size ◽  
Evolution Of Microstructure

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.

scholarly journals STRUCTURE AND PROPERTIES OF AZ31 MAGNESIUM ALLOY AFTER COMBINATION OF HOT EXTRUSION AND ECAP

2017 ◽  
Vol 23 (3) ◽  
pp. 222 ◽  
Author(s):  
Ondřej Hilšer ◽  
Stanislav Rusz ◽  
Wojciech Maziarz ◽  
Jan Dutkiewicz ◽  
Tomasz Tański ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Hot Extrusion ◽  
Az31 Magnesium Alloy ◽  
Initial State ◽  
Fine Grained ◽  
Angular Pressing ◽  
Ecap Process ◽  
Average Grain Size ◽  
Fine Grained Structure

<p>Equal channel angular pressing (ECAP) method was used for achieving very fine-grained structure and increased mechanical properties of AZ31 magnesium alloy. The experiments were focused on the, in the initial state, hot extruded alloy. ECAP process was realized at the temperature 250°C and following route Bc. It was found that combination of hot extrusion and ECAP leads to producing of material with significantly fine-grained structure and improves mechanical properties. Alloy structure after the fourth pass of ECAP tool with helix matrix 30° shows a fine-grained structure with average grain size of 2 µm to 3 µm and high disorientation between the grains. More experimental results are discussed in this article.</p>

Microstructure and Mechanical Properties Resulting from Conventional Cold Extrusion of Equal Channel Angular Extruded Aluminium Alloy AA6101

2006 ◽  
Vol 503-504 ◽  
pp. 287-292 ◽  
Author(s):  
D. Nagarajan ◽  
Chakkingal Uday ◽  
P. Venugopal
Keyword(s):  
Mechanical Properties ◽  
Equal Channel Angular Extrusion ◽  
Industrial Applications ◽  
Cold Extrusion ◽  
Fine Grained ◽  
Microstructure Evaluation ◽  
Microstructure And Mechanical Properties ◽  
Processing Step ◽  
Deformation Processes ◽  
Extruded Aluminium Alloy

Severe plastic deformation processes like equal channel angular extrusion (ECAE) have been widely investigated for their ability to produce nano/ ultra fine-grained microstructures. It is well known that submicron sized grains/ sub grains can be produced in most Al alloys using this technique. However, industrial applications of ECAE will depend heavily on the advantages conferred by this process when it is used as an intermediate processing step prior to conventional forming. In the current investigation, the influence of pre processing by ECAE on subsequent post processing by conventional cold extrusion has been investigated. ECAE extrusion was carried out on cylindrical specimens of AA 6101 using an ECAE die with a die angle of 120 degrees. Extrusion was carried out for three passes using two different processing routes. The ECA extruded specimens were subsequently subjected to conventional cold extrusion. The differences in extrusion pressures, which have a strong influence on industrial applications, were noted. Changes in microstructure and mechanical properties were also determined. The obtained results of mechanical properties and microstructure evaluation show that for high strains (strain ε ≈ 2.01), ECAE through some processing routes can be effectively used as an intermediate processing step prior to conventional cold extrusion to obtain a product with enhanced mechanical properties.

Mechanical Properties of an Accumulative Roll Bonded Aluminium Alloy Composite

2009 ◽  
Vol 618-619 ◽  
pp. 551-554 ◽  
Author(s):  
O. Al-Buhamad ◽  
M. Zakaria Quadir ◽  
Michael Ferry
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Annealing Temperature ◽  
Sheet Material ◽  
Commercial Purity ◽  
Alloy Composite ◽  
High Angle ◽  
Roll Bonding ◽  
Fine Grained ◽  
Strength And Ductility

A multilayered sheet composite of commercial purity Al and Al-0.3%Sc alloys was produced by accumulative roll bonding. The final sheet material consisted of 64 ultra fine grained layers, each of ~7.8mm in thickness. The as-deformed material was annealed at temperatures ranging from 250 to 350°C to study the changes in microstructure and their associated influence on mechanical properties. The as-deformed structures largely comprised of high angle grain boundaries in the Al layers and low angle grain boundaries in the Al(Sc) layers. During annealing, the structures in the Al(Sc) layers remained unaltered, whereas the Al layers recrystallized rapidly to the full layer thickness. The mechanical properties of the Al-Al(Sc) composite were measured and found to be unique in strength and ductility with annealing temperature having a significant influence on these properties.

Structure and Mechanical Properties of Severely Deformed Cu-Cr-Zr Alloys Produced by Accumulative Roll-Bonding Process

2008 ◽  
Vol 584-586 ◽  
pp. 791-796 ◽  
Author(s):  
Kazuo Kitagawa ◽  
T. Akita ◽  
K. Kita ◽  
Masahide Gotoh ◽  
Naoki Takata ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Ambient Temperature ◽  
Accumulative Roll Bonding ◽  
Aging Treatment ◽  
Alloy Sheet ◽  
Proof Stress ◽  
Roll Bonding ◽  
Fine Grained ◽  
Zr Alloys

Aging behavior and mechanical properties of ultra fine grained Cu-Cr-Zr alloy sheet produced by accumulative roll bonding (ARB) process were investigated. A Cu-0.85Cr-0.07Zr (in mass%) alloy was solution treated and then cold-rolled at ambient temperature in the sheet of 1 mm thick. The sheets were heavily deformed by ARB process at ambient temperature up to 5 cycles. The grain size was reduced down to 210 nm and the fraction of high angle grain boundaries (HAGB’s) in the specimen after ARB process was 63%. The proof stress ( σ 0.2) and elongation were 540 MPa and 10%, respectively. Due to the aging treatment, a little grain growth took place (240 nm) and the fraction of HAGB’s was increased to 67%. The proof stress and elongation of the aged one increased to 605 MPa and 15%, respectively. It was noteworthy that the electrical conductivity remarkably increased from 35% to 79%IACS by the aging treatment. It was concluded that the aging treatment after ARB process enhanced not only the mechanical properties but also the electrical conductivity in the Cu-Cr-Zr alloys.

Recrystallization and Grain Growth in Ultra Fine Grained Materials Produced by High Pressure Torsion

2012 ◽  
Vol 715-716 ◽  
pp. 373-373
Author(s):  
Anahita Khorashadizadeh ◽  
Myrjam Winning ◽  
Stefan Zaefferer ◽  
Dierk Raabe
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Grain Growth ◽  
High Pressure Torsion ◽  
Fine Grained ◽  
Fine Grained Material

Investigations of the microstructure of materials processed via severe plastic deformation methods such as high pressure torsion (HPT) and their recrystallization behaviour is of great interest as they are capable of producing ultra fine grained material (UFD) with good mechanical properties.

Production of Ultra-Fine-Grained Aluminum Plates by Constrained Groove Pressing Technique

2013 ◽  
Author(s):  
Hadi Miyanaji ◽  
Ali Keshavarz Panahi ◽  
Ramin Hajavifard
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Plastic Strain ◽  
Yield Strength ◽  
The Other ◽  
Fine Grained ◽  
New Methods ◽  
Pressing Operation ◽  
Resistance To Wear ◽  
Aluminum Plates

One of the new methods of producing materials that have ultra-fine grains or grains of nanometer size is the method of severe plastic deformation (SPD). In this technique, by applying severe strains to the samples, the size of the grains is reduced to the nano scale, and as a result, the mechanical properties of the metal (including the yield strength and resistance to wear and abrasion) improve considerably. In this research, the effect of the constrained groove pressing process (as one of the SPD methods) on aluminum plates was studied. In this method, two dies (one with asymmetrical grooves, and the other, flat) were used for pressing the aluminum samples. With respect to the die’s geometry, at each pressing run, a shear strain equal to 0.58 is applied to some parts of the sample. By repeating the pressing operation, a large and significant amount of plastic strain is applied throughout the sample. In the present investigation, tensile and microhardness tests were employed to determine the effect of this process on the mechanical properties of the samples,. The results showed that, by increasing the number of pressing steps, hardness and strength of the samples increase, and the elongation ability diminishes. Of course, at higher numbers of pressing steps, a little decrease in strength was observed in the samples. Complete explanations regarding this decrease have been given in the text of the article.

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