Annealing Behavior and Kinetics of Primary Recrystallization of Copper

2018 ◽  
Vol 385 ◽  
pp. 343-348 ◽  
Author(s):  
A. Morozova ◽  
A. Dolzhenko ◽  
M. Odnobokova ◽  
Alexander P. Zhilyaev ◽  
Andrey Belyakov ◽  
...  
Keyword(s):  
Cold Deformation ◽  
Rolling Direction ◽  
Annealing Treatment ◽  
Primary Recrystallization ◽  
Kolmogorov Equation ◽  
Annealing Behavior ◽  
Kernel Average Misorientation ◽  
Fractional Softening ◽  
Grain Orientation Spread ◽  
Kinetics Of

The microstructure evolution during the annealing treatment of a recycled copper after cold rolling to total strain of 2.6 was investigated. The cold deformation resulted in the elongation of initial grains along rolling direction and the strain-induced formation of subboundaries. Annealing recovery occurred in the temperature range 100-250 °C. The recrystallized microstructures were observed after annealing at 300-400 °C. The hardness of partially recrystallized copper samples was interpreted in terms of dislocation strengthening. The recrystallization kinetics was estimated according to a Johnson–Mehl–Avrami–Kolmogorov equation using different methods for recrystallized fraction determination, i.e., the fractional softening, the grain orientation spread, and the Kernel average misorientation.

Enhanced Formability of AZ31 Magnesium Alloy Sheet Processed by Equal Channel Angular Rolling and Annealing Treatment

2007 ◽  
Vol 26-28 ◽  
pp. 91-94
Author(s):  
Zhen Hua Chen ◽  
Yong Qi Cheng ◽  
Wei Jun Xia ◽  
Hong Ge Yan ◽  
Ding Chen
Keyword(s):  
Magnesium Alloy ◽  
Rolling Direction ◽  
Annealing Treatment ◽  
Alloy Sheet ◽  
Az31 Magnesium Alloy ◽  
Strain Hardening Exponent ◽  
Drawing Ratio ◽  
Magnesium Alloy Sheet ◽  
Optical Microstructure ◽  
Az31 Magnesium Alloy Sheet

In order to improve the formability of AZ31 magnesium alloy sheet at room temperature, a new process, so-called equal channel angular rolling (ECAR) and followed by annealing treatment was applied to process the sheet. The optical microstructure of the as-received sheet was similar with that of the ECARed one after annealing treatment, the Erichsen value and limiting drawing ratio of the ECARed sheet was about 6.26mm and 1.6, respectively, which was much larger than that of 4.18mm and 1.2 for the as-received sheet. These can be attributed to the low yield ratio and high strain hardening exponent due to the modified texture induced by the shear deformation during ECAR process, which is favor of the activations of basal slipping and twinning at ambient temperature, especially deforming at the rolling direction.

The Cold Rolling Effect on the Precipitation Sequence and Microstructural Changes of an Al-Mg-Si Alloy

2019 ◽  
Vol 397 ◽  
pp. 51-58
Author(s):  
Hichem Farh ◽  
Toufik Ziar ◽  
Hanna Belghit ◽  
Mourad Khechba ◽  
Abdelouahab Noua ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Rolling Mill ◽  
Rolling Direction ◽  
Coarse Particles ◽  
Microstructural Properties ◽  
Precipitation Sequence ◽  
Initial Thickness ◽  
Cold Rolled ◽  
Mechanical And Microstructural Properties ◽  
Kinetics Of

The rolling operation consists of deforming the material by passing it between two rolls whose spacing is smaller than the initial thickness of the sample, the reduction in thickness is obtained discontinuously by successive passes in the rolling mill whose spacing between the cylinders gradually decreases. This operation can influence on the mechanical and microstructural properties of the deformed materials The effect of cold rolled on microstructural evolution and precipitation sequence in Al-Mg-Si alloy has been investigated by using optical microscopy and Differential Scanning Calorimetry (DSC) in this study . The results revealed that the distribution of the grains are elongated along the rolling direction. We also noted that i nsoluble coarse particles that originated during the manufacturing process of the alloy have become visible after the rolling processes . The dislocations generated by the plastic deformation during cooled rolling constitute preferential sites for the germination and the growth of the phases, which accelerates the kinetics of the precipitation.

Mechanism of Grain Growth During Annealing of Si-Al Electrical Steel Strips Deformed in Tension

2010 ◽  
Vol 1276 ◽  
Author(s):  
J. Salinas B ◽  
A. Salinas R
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Electrical Steel ◽  
Electron Backscatter Diffraction ◽  
Steel Strip ◽  
Boundary Migration ◽  
Primary Recrystallization ◽  
Steel Strips ◽  
Grain Orientation Spread ◽  
Quality Maps

AbstractThe mechanism of recrystallization as a result of annealing during 600–7200 seconds at 700 °C of a Si-Al, low C electrical steel strip is investigated in samples deformed in tension. The evolution of grain size during annealing is evaluated by optical microscopy and electron backscatter diffraction in the scanning electron microscope. It is found that grain growth starts after an incubation time of 600 s with no apparent evidence of primary recrystallization. After that, the grain size-time relationship exhibits two different stages. Initially, the grain size increases linearly with time up to about 3600 s. During this time, some selected grains grow until they consume the deformed microstructure. In the second stage, the rate of growth decreases significantly and a final grain size of about 150 m is reached after 7200 seconds of annealing. Grain orientation spread maps obtained from EBSD data of deformed and partially recrystallized samples during the stage of linear growth reveals that the growing grains exhibit lower misorientation and therefore smaller stored energy than the non-recrystallized matrix grains. Analysis of image quality maps reveal that the IQ values for {100}<uvw>orientations are higher than those observed for {111}<uvw>orientations thus suggesting that the {100}<uvw>orientations grow at the expense of {111}<uvw>orientations by a mechanism of strain-induced boundary migration.

Effect of Austenite Deformation on Recrystallisation Behaviour in an X-70 Microalloyed Steel

2010 ◽  
Vol 89-91 ◽  
pp. 721-726 ◽  
Author(s):  
Lin Sun ◽  
Bradley P. Wynne ◽  
Eric J. Palmiere
Keyword(s):  
Microalloyed Steel ◽  
Pipeline Steel ◽  
Current Model ◽  
Compression Tests ◽  
Precipitation Kinetics ◽  
Start Time ◽  
Critical Temperatures ◽  
Softening Parameter ◽  
Fractional Softening ◽  
Kinetics Of

In the present study, the effect of austenite deformation on the recrystallisation behaviour in terms of recrystallisation-stop and recrystallisation-limit temperatures (T5% and T95%) of an X70 niobium microalloyed pipeline steel have been investigated by interrupted plane strain compression tests. The extents of recrystallisation are calculated using a modified fractional softening parameter. And the 20% and 60% of fractional softening were correlated to T5% and T95%. Quantitative optical metallography indicates that this method provides for a convenient and reliable experimental measurement of the critical temperatures associated with the recrystallisation of austenite. The recrystallisation kinetics and the precipitation kinetics of Nb(CN) were calculated using two widely applied models. The experimental results from this study suggest that the current model of precipitation kinetics might overestimate the precipitation start time.

Annealing of Amorphous Ni-Nb/Cu Overlayer Films - Thermal Groove Kinetics

1990 ◽  
Vol 181 ◽  
Author(s):  
S. N. Farrens ◽  
J. H. Perepczko
Keyword(s):  
Diffusion Processes ◽  
Effective Diffusion ◽  
Amorphous Film ◽  
Cross Sectional ◽  
Annealing Behavior ◽  
Cu Films ◽  
Cu Film ◽  
Sputter Deposited ◽  
Kinetics Of ◽  
Microstructural Examination

ABSTRACTRecent studies have shown that sputter deposited amorphous NixNb1−x (60≤×≤75) alloy films are effective diffusion barriers for operation at temperatures up to 6(X) °C[1]. The thermal stability of the amorphous films has been established on Si and GaAs substrates and may be modified by interactions wilji polycrystalline metal overlayer films. In the current work a detailed microstructural examination by cross-sectional TEM was performed on the annealing behavior of 50 nm polycrystalline Cu films on amorphous Ni60Nb40. Specifically, the development of grooves at the intersection of grain boundaries in the Cu film with both the free surface and the amorphous Ni60Nb40 base was monitored to evaluate the low temperature interfacial diffusion processes. Based upon measurements of the groove dimensions and dihedral angle during vacuum annealing at 450 °C, the surface diffusion coefficient of Cu was determined as 7.4 × 10-20 m2/sec and the surface energy for Cu derived from groove kinetics was in good agreement with other reported determinations. In addition, the grain boundary grooves that were present at the Cu/amorphous Ni60Nb40 interface in the as-deposited condition were observed to be eliminated during annealing. Again, by following the kinetics of groove healing the interfacial diffusivity was determined to be of the order of 10-28m2/sec at 500 °C and the interfacial energy for the amorphous film/Cu surface was estimated to be ≥ 340 mJ/cm2. The benefits of utilizing amorphous Ni-Nb alloys as underlays to retard thermal grooving and electromigration failure in copper arc discussed.

Effect of Aluminum Addition on the Static Recrystallization Behavior of Magnesium

2012 ◽  
Vol 724 ◽  
pp. 163-168 ◽  
Author(s):  
Keun Joon Kim ◽  
Tae Kwon Ha
Keyword(s):  
Static Recrystallization ◽  
Solution Treatment ◽  
Annealing Treatment ◽  
Hardness Measurement ◽  
Recrystallization Behavior ◽  
Microstructure Observation ◽  
Heat Treated ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Rolled Plates

Recrystallization kinetics of Mg alloy has been investigated in this study. Mg alloys such as Mg-3Al and Mg-6Al in weight percents were cast into rectangular shaped ingots of 20mm thickness. Solution treatment at 400°C for 24 hrs has been carried out on these ingots and pure Mg for comparison. Heat treated ingots including pure Mg were rolled at room temperature by thickness reductions of 10, 20, and 30 percents. Annealing treatment for recrystallization has been conducted on these cold-rolled plates at temperatures of 200, 300, and 400°C for various times from 1 min to 24 hrs. The microstructure observation and hardness measurement conducted on the recrystallized specimens revealed that static recrystallization at 200°C was very slow and expedited with increasing temperature, regardless of Al contents. While recrystallization behavior of Mg at 300°C appeared to be retarded by increase in Al contents, that of Mg was not affected at 400°C.

The Influence of Mg and Ag on the Precipitation Kinetics and the Formation of the T1 Phase in Al-Cu-Li Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 945-950 ◽  
Author(s):  
Eva Gumbmann ◽  
Frederic de Geuser ◽  
Williams Lefebvre ◽  
Christophe Sigli ◽  
Alexis Deschamps
Keyword(s):  
Cold Deformation ◽  
Precipitation Kinetics ◽  
Nucleation Kinetics ◽  
Aerospace Applications ◽  
X Ray Scattering ◽  
Common Content ◽  
Precipitate Nucleation ◽  
The Impact ◽  
Kinetics Of

Al-Cu-Li alloys are extensively used for aerospace applications. The main hardening phase is the T1phase that precipitates as thin platelets on {111}Alplanes. To facilitate its nucleation, different minor alloying elements are added and dislocations are introduced by cold deformation before the ageing treatment. The impact of these additions in combination with the presence of dislocations on precipitate nucleation and growth needs a deeper understanding. In this work, we investigated the precipitation kinetics of the T1phase in alloys containing a common content of Cu and Li and different contents of minor solutes (Mg, Ag) where these elements are present either together or independently. A general overview on the precipitation kinetics was achieved by in-situ small-angle X-ray scattering and hardness measurements. The evaluation of precipitation kinetics reveals that magnesium plays an important role during precipitation by enhancing nucleation kinetics. Additionally, a smaller yet measureable effect of Ag, both in the presence and absence of Mg has been evidenced.

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