Faceting of Twin Grain Boundaries in High‐Purity Copper Subjected to High Pressure Torsion

2019 ◽  
Vol 22 (1) ◽  
pp. 1900589 ◽  
Author(s):  
Anna Kosinova ◽  
Boris Straumal ◽  
Askar Kilmametov ◽  
Petr Straumal ◽  
Marat Bulatov ◽  
...  
Keyword(s):  
High Pressure ◽  
Grain Boundaries ◽  
High Purity ◽  
High Pressure Torsion ◽  
Purity Copper

scholarly journals The significance of self-annealing at room temperature in high purity copper processed by high-pressure torsion

2016 ◽  
Vol 656 ◽  
pp. 55-66 ◽  
Author(s):  
Yi Huang ◽  
Shima Sabbaghianrad ◽  
Abdulla I. Almazrouee ◽  
Khaled J. Al-Fadhalah ◽  
Saleh N. Alhajeri ◽  
...  
Keyword(s):  
High Pressure ◽  
High Purity ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Purity Copper

Microstructural Evolution and Micro-Compression in High-Purity Copper Processed by High-Pressure Torsion

2015 ◽  
Vol 18 (2) ◽  
pp. 241-250 ◽  
Author(s):  
Jianwei Li ◽  
Jie Xu ◽  
Chuan Ting Wang ◽  
Debin Shan ◽  
Bin Guo ◽  
...  
Keyword(s):  
High Pressure ◽  
Microstructural Evolution ◽  
High Purity ◽  
High Pressure Torsion ◽  
Purity Copper

Generation and healing of porosity in high purity copper by high-pressure torsion

2018 ◽  
Vol 145 ◽  
pp. 1-9 ◽  
Author(s):  
Yuanshen Qi ◽  
Anna Kosinova ◽  
Askar R. Kilmametov ◽  
Boris B. Straumal ◽  
Eugen Rabkin
Keyword(s):  
High Pressure ◽  
High Purity ◽  
High Pressure Torsion ◽  
Purity Copper

scholarly journals Evolution of microstructure and hardness during artificial aging of an ultrafine-grained Al-Zn-Mg-Zr alloy processed by high pressure torsion

2020 ◽  
Vol 55 (35) ◽  
pp. 16791-16805
Author(s):  
Jenő Gubicza ◽  
Moustafa El-Tahawy ◽  
János L. Lábár ◽  
Elena V. Bobruk ◽  
Maxim Yu Murashkin ◽  
...  
Keyword(s):  
High Pressure ◽  
Dislocation Density ◽  
Grain Boundaries ◽  
Artificial Aging ◽  
High Pressure Torsion ◽  
Secondary Phase ◽  
Aging Effect ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Evolution Of Microstructure

Abstract An ultrafine-grained (UFG) Al-4.8%Zn-1.2%Mg-0.14%Zr (wt%) alloy was processed by high pressure torsion (HPT) technique and then aged at 120 and 170 °C for 2 h. The changes in the microstructure due to this artificial aging were studied by X-ray diffraction and transmission electron microscopy. It was found that the HPT-processed alloy has a small grain size of about 200 nm and a high dislocation density of about 8 × 1014 m−2. The majority of precipitates after HPT are Guinier–Preston (GP) zones with a size of ~ 2 nm, and only a few large particles were formed at the grain boundaries. Annealing at 120 and 170 °C for 2 h resulted in the formation of stable MgZn2 precipitates from a part of the GP zones. It was found that for the higher temperature the fraction of the MgZn2 phase was larger and the dislocation density in the Al matrix was lower. The changes in the precipitates and the dislocation density due to aging were correlated to the hardness evolution. It was found that the majority of hardness reduction during aging was caused by the annihilation of dislocations and some grain growth at 170 °C. The aging effect on the microstructure and the hardness of the HPT-processed specimen was compared to that observed for the UFG sample processed by equal-channel angular pressing. It was revealed that in the HPT sample less secondary phase particles formed in the grain boundaries, and the higher amount of precipitates in the grain interiors resulted in a higher hardness even after aging.

Structure and Properties of Grain Boundaries in Submicrocrystalline W Obtained by Severe Plastic Deformation

2009 ◽  
Vol 283-286 ◽  
pp. 629-638 ◽  
Author(s):  
Vladimir V. Popov ◽  
Ruslan Valiev ◽  
E.N. Popova ◽  
A.V. Sergeev ◽  
A.V. Stolbovsky ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Grain Boundaries ◽  
High Pressure Torsion ◽  
Submicrocrystalline Structure ◽  
Emission Mössbauer Spectroscopy ◽  
Structure And Properties ◽  
Initial State

Submicrocrystalline structure of W obtained by severe plastic deformation (SPD) by high pressure torsion (5 revolutions of anvils at 4000C) and its thermal stability have been examined by TEM. Grain boundaries of submicrocrystalline W have been studied by the method of the emission Mössbauer spectroscopy in the initial state and after annealing at 400-6000С.

Microstructures and Mechanical Property of Ni Processed by High-Pressure Torsion and Their Evolution upon Annealing

2006 ◽  
Vol 114 ◽  
pp. 45-50 ◽  
Author(s):  
Zhi Qing Yang
Keyword(s):  
High Pressure ◽  
Grain Boundaries ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Small Difference ◽  
Dynamical Evolution ◽  
Peripheral Region ◽  
Lattice Defects ◽  
Grain Sizes ◽  
Xrd And Tem

XRD, TEM, microhardness and thermal analysis were carried out on a series of Ni samples produced by high-pressure torsion (HPT). The evolution of microstructures and their inhomogeneity were investigated. The local microstrain showed dynamical oscillations as a function of the HPT rotations, demonstrating dynamical evolution of lattice defects during the procedure. Both XRD and TEM showed that a small difference in grain sizes remains even after 5 revolutions of HPT with smaller grain sizes at the peripheral region of the sample. The higher microhardness at the peripheral region is the result of the smaller grain sizes and the higher density of lattice defects, compared with the central region. Thermal treatment at a heating rate of 20K/min from room temperature to 473K did not result in decreased microhardness, but increased by about 10% for samples treated with not more than 3 rotations of HPT. The increase in microhardness was attributed to further grain refinement, the formation of a larger fraction of high-angle grain boundaries and grain boundaries being closer to equilibrium after recovery.

The State of Grain Boundaries and Grain-Boundary Diffusion in Ultrafine-Grained Mo Obtained by Severe Plastic Deformation

2016 ◽  
Vol 367 ◽  
pp. 130-139 ◽  
Author(s):  
Vladimir V. Popov ◽  
A.V. Sergeev
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Grain Boundary ◽  
Severe Plastic Deformation ◽  
Grain Boundaries ◽  
Boundary Diffusion ◽  
High Pressure Torsion ◽  
Grain Boundary Diffusion ◽  
Fast Diffusion ◽  
Non Equilibrium

The grain-boundary diffusion of Co in ultra-fine grained Mo processed by high-pressure torsion has been studied by emission Mössbauer spectroscopy and radio-tracer analysis. It is demonstrated that under the severe plastic deformation by high-pressure torsion the non-equilibrium grain boundaries are formed which are the ultra-fast diffusion paths. At annealing in the temperature range of 623-823 K the relaxation of the non-equilibrium boundaries proceeds and their properties approach to those of equilibrium boundaries of recrystallization origin.

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