Microstructure and microhardness of cryomilled bulk nanocrystalline Al?7.5%Mg alloy consolidated by high pressure torsion

2004 ◽  
Vol 51 (3) ◽  
pp. 209-214 ◽  
Author(s):  
Z LEE
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Mg Alloy ◽  
Bulk Nanocrystalline

Bulk nanocrystalline gamma magnesium hydride with low dehydrogenation temperature stabilized by plastic straining via high-pressure torsion

2018 ◽  
Vol 157 ◽  
pp. 54-57 ◽  
Author(s):  
Kaveh Edalati ◽  
Kouki Kitabayashi ◽  
Yuji Ikeda ◽  
Junko Matsuda ◽  
Hai-Wen Li ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Magnesium Hydride ◽  
Bulk Nanocrystalline

Age-hardening of an Al–Li–Cu–Mg alloy (2091) processed by high-pressure torsion

2012 ◽  
Vol 546 ◽  
pp. 82-89 ◽  
Author(s):  
Seungwon Lee ◽  
Zenji Horita ◽  
Shoichi Hirosawa ◽  
Kenji Matsuda
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Mg Alloy ◽  
Age Hardening

Application of High-Pressure Sliding for Grain Refinement of Al and Mg Alloys

2010 ◽  
Vol 667-669 ◽  
pp. 91-96 ◽  
Author(s):  
Kiyonari Tazoe ◽  
Shuji Honda ◽  
Z. Horita
Keyword(s):  
High Pressure ◽  
Strain Rate ◽  
Grain Refinement ◽  
High Pressure Torsion ◽  
Initial Strain Rate ◽  
Mg Alloys ◽  
Initial Strain ◽  
Mg Alloy ◽  
Al Alloy ◽  
Average Grain Size

An earlier study showed that high-pressure sliding (HPS) is effective for grain refinement of pure Al in a rectangular sheet form using the principle of high-pressure torsion. In this study, the HPS is applied for grain refinement of an Al-3%Mg-0.2%Sc alloy and an AZ61 Mg alloy. HPS was conducted under a pressure of 1 GPa with sliding distances of 10 to 30 mm at room temperature for the Al alloy and at 473 K for the Mg alloy The average grain size is ~300 nm for both the Al and Mg alloys, respectively. Tensile tests showed that a superplastic elongation of ~1500% is achieved in the Al-3%Mg-0.2%Sc alloy at 573 K with an initial strain rate of 3.3x10-3 s-1 and of ~600% in the AZ61 alloy at 573 K with an initial strain rate of 1x10-3 s-1.

Aging Behavior of Al-Li-Cu-Mg Alloy Processed by High-Pressure Torsion

2010 ◽  
Vol 654-656 ◽  
pp. 1243-1246 ◽  
Author(s):  
Seung Won Lee ◽  
Daichi Akama ◽  
Z. Horita ◽  
Tetsuya Masuda ◽  
Shoichi Hirosawa ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Rolling Process ◽  
Mg Alloy ◽  
Age Hardening ◽  
Subsequent Aging ◽  
Solid Solution Treatment ◽  
Conventional Rolling

This study presents an application of high-pressure torsion (HPT) to an Al-Li-Cu-Mg alloy (2091). The alloy was subjected to solid solution treatment at 505oC for 30 minutes and was processed by HPT under 6 GPa for 5 revolutions at room temperature. The hardness increased with straining and saturated to a constant level at 225 Hv. Aging was undertaken on the HPT-processed alloy at 100, 150 and 190oC for the total periods up to 9.3 days. The aging treatment led to a further increase in the hardness to ~275 Hv. It is shown that the simultaneous strengthening of the alloy due to grain refinement and age hardening was successfully achieved by application of HPT and subsequent aging treatment. The enhancement of the strength is prominent when compared with the application of a conventional rolling process.

Bulk nanocrystalline ω-Zr by high-pressure torsion

2008 ◽  
Vol 58 (3) ◽  
pp. 219-222 ◽  
Author(s):  
M.T. Pérez-Prado ◽  
A.A. Gimazov ◽  
O.A. Ruano ◽  
M.E. Kassner ◽  
A.P. Zhilyaev
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Bulk Nanocrystalline

Effect of short-term annealing on the microstructures and flow properties of an Al–1% Mg alloy processed by high-pressure torsion

2014 ◽  
Vol 615 ◽  
pp. 231-239 ◽  
Author(s):  
Olivier Andreau ◽  
Jenő Gubicza ◽  
Nian Xian Zhang ◽  
Yi Huang ◽  
Péter Jenei ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Mg Alloy ◽  
Flow Properties ◽  
Short Term

Recovery or Non-Recovery in Al-0.1% Mg and Al-1% Mg Alloy during High-Pressure Torsion Processing

2016 ◽  
Vol 879 ◽  
pp. 773-778 ◽  
Author(s):  
Yi Huang ◽  
Justine Millet ◽  
Nian Xian Zhang ◽  
Pedro Henrique R. Pereira ◽  
Terence G. Langdon
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Mg Alloys ◽  
Rapid Recovery ◽  
Mg Alloy ◽  
Disc Diameter ◽  
Disc Centre ◽  
Evolution Behavior ◽  
Hardness Values

The Al-1% Mg and Al-0.1% Mg alloys were both processed by high-pressure torsion (HPT) at room temperature. In the Al-1% Mg alloy, the hardness values in the disc centre area are lower than in the disc edge area after 1/2 and 1 turn, and the area of lower hardness values in the disc centre decreases as the number of turns increases from 1/2 to 1 turn. Finally, the hardness values are reasonably homogenous along the disc diameter as the number of turns increases to 5 and 10 turns. The Al-0.1% Mg alloy displays a different hardness evolution behavior: the hardness values in the disc centre are higher than at the disc edge 1/2 and 1 turn, and the area of higher hardness values decreases as the numbers of turn increases from 1/2 to 1 turn. The hardness values evolve towards homogeneity along the disc diameter after 5 and 10 turns. EBSD microstructure investigations in the Al-0.1% Mg alloy reveal that a few low-angle boundaries exist at the disc edge after 1/2 turn. It is suggested that the higher hardness values in the disc centre in the Al-0.1% Mg alloy are related to rapid recovery at the disc edge where the material is subjected to heavy straining.

Deformation Twins and Stacking Faults in an AA5182 Al-Mg Alloy Processed by High Pressure Torsion

2008 ◽  
Vol 579 ◽  
pp. 147-154 ◽  
Author(s):  
M. Liu ◽  
Hans Jørgen Roven ◽  
Maxim Yu. Murashkin ◽  
Ruslan Valiev
Keyword(s):  
Molecular Dynamics ◽  
High Pressure ◽  
Molecular Dynamics Simulations ◽  
Grain Boundaries ◽  
High Pressure Torsion ◽  
Stacking Faults ◽  
Pure Metal ◽  
Mg Alloy ◽  
Transmission Electron ◽  
Dynamics Simulations

High-resolution transmission electron microscopy investigations revealed different types of deformation structures in a nanostructured commercial Al–Mg alloy processed by high pressure torsion at room temperature. Microtwins and stacking faults were detected within both nanocrystalline grains and ultrafine grains. Full dislocations in the form of dipoles were observed within grains and near the grain boundaries. Two twinning mechanisms previously predicted by molecular-dynamics simulations were directly verified including the heterogeneous twins nucleated by the successive emission of Shockley partials from grain boundaries and homogeneous twins formed in the grain interiors by the dynamic overlapping of stacking faults. Hence, the formation of full dislocations, stacking faults and twins in the present aluminum alloy subjected to severe plastic deformation may be interpreted in terms of molecular-dynamics simulations based on generalized planar fault energy curves for pure metal systems.

Hydrogen Sorption Properties of the Complex Hydride Mg2FeH6 Consolidated by HPT

2010 ◽  
Vol 667-669 ◽  
pp. 1053-1058 ◽  
Author(s):  
Gisele Ferreira De Lima ◽  
Daniel Rodrigo Leiva ◽  
Tomaz Toshimi Ishikawa ◽  
Claudemiro Bolfarini ◽  
Claudio Shyinti Kiminami ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Activation Barrier ◽  
Hydrogen Desorption ◽  
Hydrogen Atmosphere ◽  
Sorption Properties ◽  
Hydrogen Sorption ◽  
Powder Form ◽  
Reactive Milling ◽  
Bulk Nanocrystalline

In the present work, we have processed 2Mg-Fe mixtures by reactive milling (RM) under hydrogen atmosphere to synthesize Mg2FeH6 phase in the powder form which were then systematically processed by High Pressure Torsion (HPT) to produce bulk samples. The bulk samples were characterized in terms of microstructural and structural analyses and of hydrogen desorption properties. The hydrogen sorption properties after HPT processing was evaluated in comparison with the Mg2FeH6 powder obtained by RM and with commercial MgH2. HPT processing of Mg2FeH6 can produce bulks with a high density of defects that drastically lower the activation barrier for hydrogen desorption. Therefore, the bulk nanocrystalline Mg2FeH6 samples show endothermic hydrogen decomposition peak at a temperature around 320°C. In addition, when compared with the Mg2FeH6 and MgH2 powders, the Mg2FeH6 HPT disks showed the same results presented by the Mg2FeH6 powders and certainly decreases the onset transition temperature by as much as 160°C when compared with the MgH2 powders.

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