Microstructural Coarsening during Annealing of Cold Rolled Aluminum

2004 ◽  
Vol 467-470 ◽  
pp. 209-216 ◽  
Author(s):  
Q. Xing ◽  
X. Huang ◽  
Niels Hansen
Keyword(s):  
Lamellar Structure ◽  
True Strain ◽  
Rolling Texture ◽  
Recrystallization Temperature ◽  
Commercial Purity ◽  
Microstructural Coarsening ◽  
Transmission Electron ◽  
Rolled Aluminum ◽  
Cold Rolled ◽  
Commercial Purity Aluminum

The microstructural evolution during annealing below the recrystallization temperature of a commercial purity aluminum (99wt.% purity) cold rolled to a true strain of 2 has been investigated by transmission electron microscopy concentrating on microstructural and orientational aspects. The deformation microstructure was a typical lamellar structure with extended lamellar boundaries, GNBs (geometrical necessary boundaries), and short interconnecting boundaries, IDBs (incidental dislocation boundaries). The microstructure was divided into regions representing typical rolling texture orientations and regions of other orientations. During annealing the structure coarsened towards an equiaxed structure and it was observed that this coarsening was significantly slower in regions of rolling texture orientations than in regions of other orientations. This difference was discussed based on the characteristics of the deformation structure.

Large Strain Deformation and Annealing of Aluminium

2006 ◽  
Vol 519-521 ◽  
pp. 79-84 ◽  
Author(s):  
X. Huang ◽  
Q. Xing ◽  
Dorte Juul Jensen ◽  
Niels Hansen
Keyword(s):  
Lamellar Structure ◽  
Large Strain ◽  
Rolling Texture ◽  
Rolling Plane ◽  
Stored Energy ◽  
High Angle ◽  
Microstructural Parameters ◽  
Structure Correlations ◽  
Cold Rolled ◽  
Commercial Purity Aluminum

TEM, Kikuchi diffraction analyses, EBSD, neutron diffraction and hardness measurements have been applied in a study of commercial purity aluminum (AA1200) cold rolled to strains 2 and 4 and afterwards recovered by a heat treatment for 2h at temperatures up to 220 °C. The deformation microstructure is a lamellar structure delineated by dislocation boundaries and high angle boundaries ( ) parallel to the rolling plane. The macrotexture is a typical rolling texture which is composed of individual texture components present as micrometer- and submicrometre-sized volumes. In the lamellar structure, correlations have been established between microstructural parameters and the local texture, showing for example that the density of high angle boundaries and the stored energy vary locally. The local variations affect the annealing behaviors in a way that some regions coarsen faster than others, leading to a recovered structure which is heterogeneous.

scholarly journals Recovery and recrystallization in commercial purity aluminum cold rolled to an ultrahigh strain

2013 ◽  
Vol 61 (14) ◽  
pp. 5354-5364 ◽  
Author(s):  
O.V. Mishin ◽  
A. Godfrey ◽  
D. Juul Jensen ◽  
N. Hansen
Keyword(s):  
Commercial Purity ◽  
Cold Rolled ◽  
Commercial Purity Aluminum ◽  
Ultrahigh Strain

A Model for Recovery Kinetics of Aluminum after Large Strain

2012 ◽  
Vol 715-716 ◽  
pp. 374-379 ◽  
Author(s):  
Tian Bo Yu ◽  
Niels Hansen
Keyword(s):  
Present Model ◽  
Large Strain ◽  
True Strain ◽  
Commercial Purity ◽  
Recovery Model ◽  
Commercial Purity Aluminum ◽  
Kinetics Of

A model is suggested to analyze recovery kinetics of heavily deformed aluminum. The model is based on the hardness of isothermal annealed samples before recrystallization takes place, and it can be extrapolated to longer annealing times to factor out the recrystallization component of the hardness for conditions where recovery and recrystallization overlap. The model is applied to the isothermal recovery at temperatures between 140 and 220°C of commercial purity aluminum deformed to true strain 5.5. EBSD measurements have been carried out to detect the onset of discontinuous recrystallization. Furthermore, comparison between the present model and a similar recently developed recovery model is made, and the result is discussed.

A TEM Study of Dynamic Continuous Recrystallization in a Superplastic AL-4MG-0.3SC Alloy

1999 ◽  
Vol 601 ◽  
Author(s):  
L.M. Dougherty ◽  
I.M. Robertson ◽  
J.S. Vetrano
Keyword(s):  
True Strain ◽  
Orientation Imaging Microscopy ◽  
Superplastic Forming ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
In Situ Experiments ◽  
Continuous Recrystallization ◽  
Cold Rolled ◽  
Nominal Temperature

AbstractAn Al-4Mg-0.3Sc alloy, aged at 280°C for 8 hours and cold rolled to a 70% reduction, exhibited dynamic recrystallization during superplastic forming at 460°C and at a strain rate of 10−3sec−1. To understand the progression of recrystallization during forming, specimens were deformed under these same conditions to 0.1, 0.2, 0.4 and 0.8 true strain and studied postmortem using optical microscopy, transmission electron microscopy and orientation imaging microscopy. The microstructural evolution that occurred between each strain state was directly observed during deformation experiments at a nominal temperature of 460°C in the transmission electron microscope. These in-situ experiments showed the migration, coalescence, disintegration and annihilation of subboundaries. This combination of post-mortem analysis of specimens strained in bulk with real time observations made during these in-situ experiments allows the mechanisms operating during dynamic continuous recrystallization to be ascertained.

In Situ EBSD Investigation of Recrystallization in a Partially Annealed and Cold-Rolled Aluminum Alloy of Commercial Purity

2011 ◽  
Vol 14 (1-2) ◽  
pp. 39-44 ◽  
Author(s):  
Anne-Laure Helbert ◽  
Wei Wang ◽  
François Brisset ◽  
Thierry Baudin ◽  
Richard Penelle
Keyword(s):  
Aluminum Alloy ◽  
Commercial Purity ◽  
Rolled Aluminum ◽  
Cold Rolled

Microstructure, Mechanical and Corrosion Properties of 5E61 Alloy

2017 ◽  
Vol 898 ◽  
pp. 29-34
Author(s):  
Pei Liang Liu ◽  
Xiao Lan Wu ◽  
Sheng Ping Wen ◽  
Hui Huang ◽  
Kun Yuan Gao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mass Loss ◽  
Dendritic Structure ◽  
Recrystallization Temperature ◽  
Corrosion Properties ◽  
Exfoliation Corrosion ◽  
Transmission Electron ◽  
Cold Rolled ◽  
Mechanical And Corrosion Properties ◽  
Scanning Electron

The microstructure of Al-6Mg-0.9Mn-0.07Zr-0.2Er (wt.%), registered as 5E61 alloy, were investigated using optical microscopy, scanning electron microscopy and transmission electron microscopy. The results showed that the addition of 0.2 wt.% Er can refine the dendritic structure and form fine and coherent L12 structured Al3(ErxZr1-x) precipitates in the alloy. After a two-stage homogenization (280°C/10h, 460°C/36h), the recrystallization temperature of the alloy with 0.2 wt.% Er is about 15°C higher than that of the alloy without Er. The better recrystallization resistance may be related to the Al3(ErxZr1-x) precipitates, which can pin on dislocations and sub-grain boundaries. The hardness of the cold-rolled alloy with 0.2 wt.% Er is 143HV, which is 5% higher than the alloy without Er. The exfoliation corrosion and nitric acid mass loss test were also performed. The exfoliation corrosion of the alloy is N grade, and the mass loss is only 9.84mg/cm2.

Texture Manipulation in Commercial Purity Aluminum by Deformation Path Change from ECAP to Plane Strain Compression

2010 ◽  
Vol 667-669 ◽  
pp. 445-450
Author(s):  
Ehab A. El-Danaf ◽  
Mahmoud S. Soliman ◽  
Abdulhakim A. Almajid
Keyword(s):  
Plane Strain ◽  
Rolling Texture ◽  
Plane Strain Compression ◽  
Commercial Purity ◽  
Plane Normal ◽  
Angular Pressing ◽  
Microstructure Parameters ◽  
Commercial Purity Aluminum ◽  
1050 Aluminum Alloy ◽  
Evolution Of Microstructure

Electron back scattered diffraction (EBSD) was used to document the microstructure and texture developed due to cross deformation of commercial purity 1050 aluminum alloy. The materials was first deformed in equal channel angular pressing die (ECAP) to one and two passes, via route BC and then deformed in plane strain compression (PSC) to two axial true plastic strain values of 0.5 and 1.0. The study provides a documentation of the evolution of microstructure parameters namely; cell size, misorientation angle, fraction of submicron grain size and fraction of high angle grain boundaries. These microstructure parameters were investigated on the plane normal to the loading direction in PSC (RD-TD). These microstructure parameters are compared to those achieved due to the ECAP process only. The ideal rolling texture orientations are depicted and crystal orientation maps were generated. The spatial distribution of grains having these orientations are revealed through these maps. The fraction of the main texture components for a 10o spread around the specified orientations is experimentally calculated and a quantitative idea on the evolution of microtexture is presented.

3D microband boundary alignments and transitions in a cold rolled commercial purity aluminum alloy

2013 ◽  
Vol 79 ◽  
pp. 15-21 ◽  
Author(s):  
C. George ◽  
B. Soe ◽  
K. King ◽  
M.Z. Quadir ◽  
M. Ferry ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Commercial Purity ◽  
Cold Rolled ◽  
Commercial Purity Aluminum

Grain Boundary Structures of ARB Processed Aluminum

2008 ◽  
Vol 584-586 ◽  
pp. 716-721 ◽  
Author(s):  
Seiichiro Ii ◽  
Motoki Hishida ◽  
Naoki Takata ◽  
Kenichi Ikeda ◽  
Hideharu Nakashima ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundary ◽  
Dislocation Model ◽  
Commercial Purity ◽  
Roll Bonding ◽  
Transmission Electron ◽  
The Common ◽  
The Difference ◽  
Commercial Purity Aluminum

Grain boundary structures in the commercial purity aluminum (1100Al) highly deformed by the accumulative roll bonding (ARB) process was observed by using conventional transmission electron microscopy (CTEM) and high resolution transmission electron microscopy (HRTEM). In the low angle grain boundary with a tilt angle (2θ) of 2.1o consisted of the periodic dislocations array, the interval of those dislocations could be explained by the dislocation model for grain boundary. However, the dense dislocation region locally existed at the vicinity of the low angle boundary. On the other hand, we also observed the high angle grain boundary of which the common axis and 2θ was <110> and 125.9o, respectively. In this grain boundary, we could describe the boundary configuration in terms of the combination of the kite-shaped structure unit characterized by Σ11 coincidence boundary with the 2θ of 129.52o around <110> and the additional dislocations to compensate the difference of the actual and geometrically coincided one.

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