Post-shear deformation of high pressure torsion-deformed nickel under hydrostatic pressure

2007 ◽  
Vol 56 (9) ◽  
pp. 757-760 ◽  
Author(s):  
M. Hafok ◽  
R. Pippan
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Shear Deformation ◽  
High Pressure Torsion

Hydrostatic pressure effects on superconducting transition of nanostructured niobium highly strained by high-pressure torsion

2019 ◽  
Vol 125 (12) ◽  
pp. 125901 ◽  
Author(s):  
Masaki Mito ◽  
Yuichiro Kitamura ◽  
Takayuki Tajiri ◽  
Kazuma Nakamura ◽  
Ryo Shiraishi ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Pressure Torsion ◽  
Pressure Effects ◽  
Superconducting Transition ◽  
Highly Strained

Texture Evolution of HPT-Processed Ni50Mn29Ga21

2011 ◽  
Vol 702-703 ◽  
pp. 169-172 ◽  
Author(s):  
Robert Chulist ◽  
Andrea Böhm ◽  
E. Rybacki ◽  
T. Lippmann ◽  
C.G. Oertel ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Synchrotron Radiation ◽  
High Pressure Torsion ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
Residual Austenite ◽  
High Energy ◽  
Electron Backscatter ◽  
Backscatter Diffraction

The texture of polycrystalline Ni50Mn29Ga21alloys fabricated by high pressure torsion (HPT) was investigated with high-energy synchrotron radiation. HPT was performed at temperatures between 873K and 1173K under a hydrostatic pressure of 400 MPa. During HPT above 973K the initial cyclic fibre texture changes to a strong cube and a weak F component. Below 973K a strong rotated cube and weak F and C components develop. Additionally, electron backscatter diffraction reveals that samples deformed at low temperature do not completely transform to martensite giving rise to residual austenite.

scholarly journals Real Hydrostatic Pressure in High-Pressure Torsion Measured by Bismuth Phase Transformations and FEM Simulations

2016 ◽  
Vol 57 (4) ◽  
pp. 533-538 ◽  
Author(s):  
Kaveh Edalati ◽  
Dong Jun Lee ◽  
Takashi Nagaoka ◽  
Makoto Arita ◽  
Hyoung Seop Kim ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Phase Transformations ◽  
High Pressure Torsion ◽  
Fem Simulations

scholarly journals In-Situ Synchrotron Profile Analysis after High-Pressure Torsion Deformation

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 232 ◽  
Author(s):  
Michael Kerber ◽  
Florian Spieckermann ◽  
Roman Schuster ◽  
Bertalan Joni ◽  
Norbert Schell ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Pressure Torsion ◽  
Profile Analysis ◽  
Heating Process ◽  
Line Profile Analysis ◽  
X Ray ◽  
Pressure Release ◽  
Induced Defects

The presence of hydrostatic pressure is a general crucial characteristic of severe plastic deformation methods for reaching high strains and for introducing large quantities of lattice defects, which are necessary to establish new grain boundaries. Insights into the processes occurring during deformation and the influence of hydrostatic pressure are necessary to help better understand the SPD methods. A special experimental procedure was designed to simulate the hydrostatic pressure release: High pressure torsion (HPT)-deformed microstructure changes related to the release of hydrostatic pressure after the HPT deformation of copper and nickel were studied by freezing the sample before releasing the pressure. High-resolution in-situ X-ray diffraction of the heating process was performed using synchrotron radiation in order to apply X-ray line profile analysis to analyze the pressure release. The results on copper and nickel generally indicated the influence of hydrostatic pressure on the mobility and interaction of deformation-induced defects as well as the resulting microstructure.

scholarly journals Amorphous-Nanocrystalline Composites Prepared by High-Pressure Torsion

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 511 ◽  
Author(s):  
Inga Permyakova ◽  
Alex Glezer
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Hydrostatic Pressure ◽  
Severe Plastic Deformation ◽  
Amorphous Alloys ◽  
Preparation Method ◽  
High Pressure Torsion ◽  
Structure And Properties ◽  
Nanocrystalline Composites

This article presents systematic studies of the preparation method and the specific features of the changes in the structure and properties of amorphous-nanocrystalline composites formed from melt-quenched ribbons of iron- and cobalt-based amorphous alloys and the Cu-Nb crystalline nanolaminates by severe plastic deformation by torsion in the Bridgeman chamber at high quasi-hydrostatic pressure.

Hydrogen Storage, Microstructure and Mechanical Properties of Strained Mg65Ni20Cu5Y10 Metallic Glass

2012 ◽  
Vol 729 ◽  
pp. 74-79
Author(s):  
Ádám Révész ◽  
Ágnes Kis-Tóth ◽  
Péter Szommer ◽  
Tony Spassov
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Shear Deformation ◽  
High Pressure Torsion ◽  
Hydrogen Uptake ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melt Spun ◽  
Lower Temperature ◽  
Scanning Electron

Melt-spun amorphous Mg65Ni20Cu5Y10metallic glass compacts were subjected to severe shear deformation by high-pressure torsion. High-resolution X-ray diffraction analysis and scanning electron microscopy revealed that high-pressure torsion resulted in a deformation dependent microstructure. Nanoindentation measurements indicated that the heavy shear deformation yields an increase in hardness. High-pressure calorimetry measurements revealed that hydrogen uptake in the fully amorphous alloy occurs at a significantly lower temperature compared to the fully crystallized state, while the amount of absorbed hydrogen increased considerably after shear strain due to the formation of Mg2Ni crystals.

Effect of Hydrostatic Pressure on the Microstructure and Mechanical Properties during and after High Pressure Torsion

2010 ◽  
Vol 667-669 ◽  
pp. 657-664 ◽  
Author(s):  
Erhard Schafler
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Pressure Torsion ◽  
Profile Analysis ◽  
Hardness Measurement ◽  
Relaxation Processes ◽  
Line Profile Analysis ◽  
Subgrain Structure ◽  
Pressure Release

The presence of a hydrostatic pressure as a general feature of SPD methods is essential for achieving the high strains and the introduction of the high amount of lattice defects, which are necessary to establish new grain boundaries. Systematic investigations of High Pressure Torsion (HPT)-deformed Cu under variation of strain and hydrostatic pressure revealed marked differences between the in-situ torsional stress (torque measurement) and the post-HPT strength of the ultrafine-grained materials. These facts let assume the occurrence of relaxation processes (recovery/recrystallisation) of static character with respect to the release of the hydrostatic pressure after straining. In order to gain insight into the processes behind, a special experimental procedure was designed to simulate the hydrostatic pressure release. Investigations by X-ray line profile analysis and hardness measurement show marked influences of the pressure release on microstructure and strength. While the size of the coherently scattering domains is not strongly affected, the dislocation density decreases drastically and the arrangement of the dislocations within the subgrain structure changes to a less stress intensive one, upon the pressure release. In parallel the hardness decreases significantly and confirms the discrepancy between in-situ torque-stress and post-HPT strength.

High Pressure Torsion of Rail Steels

2006 ◽  
Vol 503-504 ◽  
pp. 455-460 ◽  
Author(s):  
F. Wetscher ◽  
Bao Hui Tian ◽  
Richard Stock ◽  
Reinhard Pippan
Keyword(s):  
High Pressure ◽  
Flow Stress ◽  
Mechanical Strength ◽  
Shear Deformation ◽  
Strain Path ◽  
High Pressure Torsion ◽  
Cyclic Form ◽  
Dislocation Densities ◽  
Mechanical Strengths

To study the influence of shear deformation on the evolution of the microstructure and the mechanical strength in rail steels, three steels with different microstructure (two pearlitic, one bainitic) were deformed by High Pressure Torsion (HPT). In order to evaluate in addition the effect of the strain path, a cyclic form of HPT was applied. The mechanical strength was determined by means of in-situ measurement of the flow stress and microhardness measurements. The differences of the mechanical strengths between the monotonic and cyclic deformed samples clearly indicate that a monotonic deformation promotes higher dislocation densities and leads to the assumption that dissolution of the cementite takes place more pronounced.

Sign in / Sign up

Export Citation Format

Share Document