Atomic-scale investigation on the structural evolution and deformation behaviors of Cu–Cr nanocrystalline alloys processed by high-pressure torsion

2020 ◽  
Vol 832 ◽  
pp. 154994
Author(s):  
Qinqin Shao ◽  
Jinming Guo ◽  
Jianghua Chen ◽  
Zaoli Zhang
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Structural Evolution ◽  
Nanocrystalline Alloys ◽  
Atomic Scale ◽  
Deformation Behaviors

Intermixing of Fe and Cu on the Atomic Scale by High-Pressure Torsion as Revealed by Dc- and Ac-Squid Susceptometry

2020 ◽  
Author(s):  
Martin Stückler ◽  
Heinz Krenn ◽  
Lukas Weissitsch ◽  
Stefan Wurster ◽  
Reinhard Pippan ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Atomic Scale

Strengthening of Nickel Deformed by High Pressure Torsion

2008 ◽  
Vol 584-586 ◽  
pp. 417-421 ◽  
Author(s):  
Hong Wang Zhang ◽  
X. Huang ◽  
Niels Hansen ◽  
Reinhard Pippan ◽  
Michael Zehetbauer
Keyword(s):  
High Pressure ◽  
Cold Rolling ◽  
High Pressure Torsion ◽  
Structural Evolution ◽  
Longitudinal Section ◽  
High Angle ◽  
Microstructural Parameters ◽  
Transmission Electron ◽  
Structure Relationship ◽  
Von Mises

The strength of a deformed metal depends on the content of high angle boundaries, low angle dislocation boundaries and the dislocations between the boundaries. High angle boundaries contribute by Hall-Petch strengthening, whereas for the low angle dislocation boundaries and dislocations between boundaries the strengthening is proportional to the square root of the dislocation density. Based on an assumption of additivity of these contributions, the flow stresses of metals deformed by cold rolling have been calculated successfully. In the present investigation pure Ni (99.9%) has been deformed by high pressure torsion (HPT) to von Mises strains of 0.9, 1.7, 8.7 and 12. The strength of the HPT Ni has been determined by Vickers microhardness (HV) measurements and the microstructural parameters have been determined by transmission electron microscope (TEM) in the longitudinal section. HPT has been compared with deformation by cold rolling and torsion based on the structural evolution with strain and the stress-structure relationship. Based on an assumption of a linear additivity of boundary strengthening and dislocation strengthening, good agreement has been found between the calculated and the experimental flow stress.

High Pressure Torsion of Intermetallic Zr3Al

2008 ◽  
Vol 584-586 ◽  
pp. 553-558 ◽  
Author(s):  
David Geist ◽  
Christian Rentenberger ◽  
Hans Peter Karnthaler
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Structural Evolution ◽  
Nanocrystalline Structure ◽  
Temperature Dependent ◽  
Transmission Electron ◽  
Ordered Alloys ◽  
Grain Fragmentation ◽  
Shear Strains

The L12-structured intermetallic compound Zr3Al can be rendered amorphous easily by several techniques. In the present study the structural evolution during high pressure torsion (HPT) was investigated systematically by transmission electron microscopy (TEM) methods. Zr3Al samples were deformed at room temperature to different grades of deformation up to shear strains of 140 000%. TEM investigations revealed that the tendency to grain fragmentation, disordering and the formation of a nanocrystalline structure is weak compared to other L12 ordered alloys like Ni3Al. In addition, an amorphous phase has not been encountered. The present results differ strongly from previous ones obtained from ball-milled materials. Possible reasons for the different behavior are discussed on the basis of the temperature dependent dissociation scheme of the superlattice dislocations gliding in Zr3Al.

Structural Evolution on the Cross-Section of an AZ31 Magnesium Alloy Processed by High-Pressure Torsion

2010 ◽  
Vol 667-669 ◽  
pp. 247-252 ◽  
Author(s):  
Roberto B. Figueiredo ◽  
Terence G. Langdon
Keyword(s):  
High Pressure ◽  
Magnesium Alloy ◽  
Cross Section ◽  
High Pressure Torsion ◽  
Shear Bands ◽  
Structural Evolution ◽  
Grain Structure ◽  
Az31 Magnesium Alloy ◽  
Average Grain Size ◽  
The Cross

Disks of an AZ31 magnesium alloy were processed by High-Pressure Torsion (HPT) at 463 K to different numbers of rotations. The grain structure was evaluated along the cross-section of the disks using optical microscopy. Significant heterogeneities in the average grain size were observed in areas of the disks which were located at similar distances to the center but at different distances from the surface. Moreover, different grain structures were observed in neighboring areas and shear bands occurred at several locations in the disks. Microhardness tests revealed differences in the strength of the material as a function of the distance to the surface. An analysis of the grain structure and hardness distribution suggests the occurrence of flow localization in HPT processing.

scholarly journals Synthesis of Hybrid Nanocrystalline Alloys by Mechanical Bonding through High‐Pressure Torsion

2020 ◽  
Vol 22 (4) ◽  
pp. 1901289 ◽  
Author(s):  
Jae-Kyung Han ◽  
Taylor Herndon ◽  
Jae-il Jang ◽  
Terence G. Langdon ◽  
Megumi Kawasaki
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Nanocrystalline Alloys ◽  
Mechanical Bonding

Structural evolution during nanostructuring of additive manufactured 316L stainless steel by high-pressure torsion

2021 ◽  
pp. 130364
Author(s):  
Jae-Kyung Han ◽  
Xiaojing Liu ◽  
Isshu Lee ◽  
Yulia O. Kuzminova ◽  
Stanislav A. Evlashin ◽  
...  
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
316L Stainless Steel ◽  
High Pressure Torsion ◽  
Structural Evolution

TEM investigations of the structural evolution in a pearlitic steel deformed by high-pressure torsion

2006 ◽  
Vol 37 (6) ◽  
pp. 1963-1968 ◽  
Author(s):  
F. Wetscher ◽  
R. Pippan ◽  
S. Sturm ◽  
F. Kauffmann ◽  
C. Scheu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Structural Evolution ◽  
Pearlitic Steel

Consolidation of High Performance AA6061 and AA6061-SiCp Composite Processed by High Pressure Torsion

2014 ◽  
Vol 783-786 ◽  
pp. 2623-2628 ◽  
Author(s):  
W.H. El-Garaihy ◽  
El Sayed M.A. Rassoul ◽  
Hanadi G. Salem
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
Electron Microscope ◽  
High Performance ◽  
High Pressure Torsion ◽  
Structural Evolution ◽  
Triple Junctions ◽  
Hot Compaction ◽  
Before And After ◽  
Scanning Electron

Discs of monolithic AA6061 and AA6061 reinforced with SiCp were processed via combination of hot compaction of the mixed powders followed by high pressure torsion (HPT). HPT processing was investigated using incremental revolutions up to four, under pressures of 1 and 3 GPa. Structural evolution of the powders before and after HPT processing was investigated using scanning electron microscope (SEM). HPT processing of AA6061 discs produced a trimodel structure with micron-scale grains, subgrains and nanoscale substructure of 29, 1.9 μm, and 250 nm, respectively. Reinforcement with SiCp resulted in a refined structure with micron-scale grains, subgrains and nanoscale substructure of 25, 1.9 μm, and 184 nm respectively. The presence of SiCp at the triple junctions and along the grain boundaries enhanced the rate of strain hardening of the Al-matrices and significantly refined the grain size. More pronounced refinements of the grains, subgrains, and substructures were observed with increasing the HPT pressure up to 3 GPa.

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