scholarly journals On the Heterogeneity of Local Shear Strain Induced by High‐Pressure Torsion

2019 ◽  
Vol 22 (1) ◽  
pp. 1900477 ◽  
Author(s):  
Wei Jiang ◽  
Hao Zhou ◽  
Yang Cao ◽  
Jinfeng Nie ◽  
Yusheng Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Shear Strain ◽  
High Pressure Torsion ◽  
Local Shear

Formation of Bulk Nanostructured Al3Ni from Elemental Micropowders Using High-Pressure Torsion

2013 ◽  
Vol 765 ◽  
pp. 378-382 ◽  
Author(s):  
Ali Alhamidi ◽  
Kaveh Edalati ◽  
Zen Ji Horita
Keyword(s):  
High Pressure ◽  
Diffusion Coefficient ◽  
Shear Strain ◽  
Melting Temperature ◽  
High Pressure Torsion ◽  
Processing Temperature ◽  
Powder Mixtures

The formation of bulk nanograined Al3Ni intermetallics from elemental micro-powder mixtures of Al-25 mol.% Ni are studied after processing by high-pressure torsion (HPT) for various turns at 473 K and at 573 K. It is found that nanograined Al3Ni intermetallics with high angles of misorientation are produced at temperatures well below the melting temperature. The fraction of Al3Ni intermetallics increases by increasing the shear strain and increasing the HPT processing temperature. During HPT, both Ni and Al atoms diffuse significantly in each other with a diffusion coefficient well comparable to the atomic interdiffusion in the Al3Ni intermetallic at its melting temperature.

scholarly journals Assessment of homogeneity of the shear-strain pattern in Al–7wt%Si casting alloy processed by high-pressure torsion

2014 ◽  
Vol 597 ◽  
pp. 102-110 ◽  
Author(s):  
C.M. Cepeda-Jiménez ◽  
A. Orozco-Caballero ◽  
J.M. García-Infanta ◽  
A.P. Zhilyaev ◽  
O.A. Ruano ◽  
...  
Keyword(s):  
High Pressure ◽  
Shear Strain ◽  
High Pressure Torsion ◽  
Casting Alloy ◽  
Strain Pattern

scholarly journals Hydrolytic Hydrogen Production on Al–Sn–Zn Alloys Processed by High-Pressure Torsion

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1209 ◽  
Author(s):  
Fan Zhang ◽  
Kaveh Edalati ◽  
Makoto Arita ◽  
Zenji Horita
Keyword(s):  
High Pressure ◽  
Hydrogen Production ◽  
Shear Strain ◽  
Pitting Corrosion ◽  
Hydrogen Generation ◽  
High Pressure Torsion ◽  
Generation Rate ◽  
Phase Mixing ◽  
Zn Alloy ◽  
Zn Alloys

Aluminium-tin-based alloys with different compositions were synthesized by a high-pressure torsion (HPT) method. The effect of different alloying elements and processing routes on the hydrogen generation performance of the alloys was investigated. The results show that Zn can enhance the hydrogen generation rate and yield by promoting pitting corrosion. The highest reactivity in water was achieved for an Al-30wt %Sn-10wt %Zn alloy. Detailed analysis of the Al-30wt %Sn-10wt %Zn alloy shows that increasing the shear strain and the resultant formation of ultrafine grains and phase mixing enhance the hydrogen generation rate through the effects of both nanogalvanic cells and pitting corrosion.

A visualization of shear strain in processing by high-pressure torsion

2010 ◽  
Vol 45 (3) ◽  
pp. 765-770 ◽  
Author(s):  
Y. Cao ◽  
Y. B. Wang ◽  
S. N. Alhajeri ◽  
X. Z. Liao ◽  
W. L. Zheng ◽  
...  
Keyword(s):  
High Pressure ◽  
Shear Strain ◽  
High Pressure Torsion

Cooperative Grain Boundary Sliding and Shear Banding at High Strains in Ultrafine Grained and Nanocrystalline Pd Alloys

2010 ◽  
Vol 667-669 ◽  
pp. 649-656
Author(s):  
Yulia Ivanisenko ◽  
Hans Jörg Fecht
Keyword(s):  
High Pressure ◽  
Grain Boundary ◽  
Shear Strain ◽  
High Pressure Torsion ◽  
Mechanical Test ◽  
Shear Bands ◽  
Grain Boundary Sliding ◽  
Materials Testing ◽  
Ultrafine Grained ◽  
Boundary Sliding

Instrumented high pressure torsion, i.e. mechanical test in a torsion mode under high pressure, allows interesting possibility of materials testing, because materials mechanical response can be studied in a practically unlimited shear strain range. We have studied microstructures formed in initially coarse crystalline and nanocrystalline (nc) Pd and its alloys after instrumented HPT up to shear strain 300, and revealed signatures of similar processes occurring in all these materials. In particular, we found traces of cooperative grain boundary sliding in the form of aligned in parallel segments of boundaries of several grains with straightened triple points. Fracture surfaces contained shear bands. Texture measurements revealed lower dislocation activity in nanocrystalline state as compared with coarse crystalline one. Therefore we argue that cooperative grain boundary sliding is an important deformation mechanism at large strain which develops in both ultrafine grained (ufg) and nanocrystalline materials. In nc and ufg materials planes of cooperative grain boundary sliding act as precursors of shear bands and shear occurs along planes formed by numerous grain boundaries.

Three-dimensional shear-strain patterns induced by high-pressure torsion and their impact on hardness evolution

2011 ◽  
Vol 59 (10) ◽  
pp. 3903-3914 ◽  
Author(s):  
Y. Cao ◽  
Y.B. Wang ◽  
R.B. Figueiredo ◽  
L. Chang ◽  
X.Z. Liao ◽  
...  
Keyword(s):  
High Pressure ◽  
Shear Strain ◽  
High Pressure Torsion ◽  
Three Dimensional

Microstructural and textural evolution of calcite deformed to high shear strain by high-pressure torsion

2019 ◽  
Vol 118 ◽  
pp. 32-47 ◽  
Author(s):  
Roman Schuster ◽  
Gerlinde Habler ◽  
Erhard Schafler ◽  
Rainer Abart
Keyword(s):  
High Pressure ◽  
Shear Strain ◽  
High Pressure Torsion ◽  
High Shear ◽  
Textural Evolution

scholarly journals Correlation between TEM, SAXS and DSC to investigate the influence of SPD on precipitation mechanisms of an Al-Zn-Mg-Cu alloy

2020 ◽  
Vol 326 ◽  
pp. 08006
Author(s):  
Amandine Duchaussoy ◽  
Alexis Deschamps ◽  
Xavier Sauvage ◽  
Frédéric De Geuser ◽  
Zenji Horita
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Shear Strain ◽  
Size Distribution ◽  
High Pressure Torsion ◽  
Solute Segregation ◽  
Dynamic Precipitation ◽  
Precipitation Kinetics ◽  
Cu Alloy

This study allowed to understand the influence of severe plastic deformation by High Pressure Torsion (HPT) on an Al-Zn-Mg-Cu alloy and more especially the influence on precipitation mechanisms thanks to the correlation between DSC, SAXS and STEM data. A shear strain of γ ≈ 200 was first applied to the alloy. This deformation leads to nanostructuration, creation of high density of defects but also solute segregation to boundaries and dynamic precipitation. These specific microstructural features give rise to an acceleration of precipitation kinetics during heat treatments but also to a lower precipitation temperature and a modification of final precipitates size distribution as compared to the un-deformed alloy.

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