scholarly journals In situ atomic scale mechanisms of strain-induced twin boundary shear to high angle grain boundary in nanocrystalline Pt

2018 ◽  
Vol 195 ◽  
pp. 69-73 ◽  
Author(s):  
Lihua Wang ◽  
Jiao Teng ◽  
Yu Wu ◽  
Xuechao Sha ◽  
Sisi Xiang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Twin Boundary ◽  
Atomic Scale ◽  
High Angle ◽  
Boundary Shear

In situ observation of multiple parallel (1 1 1) twin boundary formation from step-like grain boundary during Si solidification

2020 ◽  
Vol 13 (10) ◽  
pp. 105501
Author(s):  
Kuan-Kan Hu ◽  
Kensaku Maeda ◽  
Keiji Shiga ◽  
Haruhiko Morito ◽  
Kozo Fujiwara
Keyword(s):  
Grain Boundary ◽  
Twin Boundary ◽  
In Situ Observation ◽  
Boundary Formation

Mechanism of Stress-Driven Grain Boundary Migration in Nanotwinned Materials

2018 ◽  
Vol 55 (1) ◽  
pp. 21-25 ◽  
Author(s):  
N.V. Skiba
Keyword(s):  
Theoretical Model ◽  
Grain Boundary ◽  
Twin Boundary ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
High Angle ◽  
Twin Boundaries ◽  
Critical Stresses ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials

Abstract Stress-driven grain boundary (GB) migration in ultrafine-grained materials with nanotwinned structure is theoretically described. In the framework of the theoretical model, the stress-driven high-angle GB migration is accompanied by migration of twin boundaries which adjoin this GB. Energetic characteristics and critical stresses of the GB migration accompanied by the twin boundary migration are calculated.

Grain boundary shear–migration coupling—I. In situ TEM straining experiments in Al polycrystals

2009 ◽  
Vol 57 (7) ◽  
pp. 2198-2209 ◽  
Author(s):  
F. Mompiou ◽  
D. Caillard ◽  
M. Legros
Keyword(s):  
Grain Boundary ◽  
In Situ Tem ◽  
Boundary Shear

Investigation on quenching at a high-angle Cu grain boundary on an atomic scale

2006 ◽  
Vol 15 (3) ◽  
pp. 610-617 ◽  
Author(s):  
Zhang Lin ◽  
Wang Shao-Qing ◽  
Ye Heng-Qiang
Keyword(s):  
Grain Boundary ◽  
Atomic Scale ◽  
High Angle

Indentation-Induced Deformation Behavior in Martensitic Steel Observed through In Situ Nanoindentation in a Transmission Electron Microscopy

2006 ◽  
Vol 503-504 ◽  
pp. 239-244 ◽  
Author(s):  
Takahito Ohmura ◽  
A. Minor ◽  
Kaneaki Tsuzaki ◽  
J.W. Morris
Keyword(s):  
Grain Boundary ◽  
Deformation Behavior ◽  
Critical Stress ◽  
Martensitic Steel ◽  
High Angle ◽  
Block Boundary ◽  
Density Of Dislocations ◽  
Transmission Electron ◽  
Pile Up

Deformation behavior in the vicinity of grain boundary in Fe-0.4wt%C tempered martensitic steel were studied through in-situ nanoindentation in a TEM. Two types of boundaries were imaged in the dislocated martensitic structure: a low-angle lath boundary and a high-angle block boundary. In the case of a low-angle grain boundary, the dislocations induced by the indenter piled up against the boundary. As the indenter penetrated further, a critical stress appears to have been reached and a high density of dislocations was suddenly emitted on the far side of the grain boundary into the adjacent grain. In the case of the high-angle grain boundary, the numerous dislocations that were produced by the indentation were simply absorbed into the boundary, with no indication of pile-up or the transmission of strain.

scholarly journals In Situ Atomic-Scale Observation of Dislocation Climb and Grain Boundary Transformation in Nanostructured Metal

2021 ◽  
Author(s):  
Shufen Chu ◽  
Pan Liu ◽  
Yin Zhang ◽  
Xiaodong Wang ◽  
Shuangxi Song ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Grain Boundary ◽  
Room Temperature ◽  
Atomic Plane ◽  
Dislocation Core ◽  
Dislocation Climb ◽  
Atomic Scale ◽  
Atomic Column ◽  
Nanostructured Metal

Abstract We report atomic-scale observations of grain boundary (GB) dislocation climb in nanostructured Au during in situ straining at room temperature. Climb of a dislocation occurs by stress-induced reconstruction of two atomic columns at the edge of an extra half atomic plane in the dislocation core. Different from the conventional belief of dislocation climb by destruction or construction of a single atomic column at the dislocation core, the new atomic route is demonstrated to be energetically favorable by Monte Carlo simulations. Our in situ observations also reveal GB transformation through dislocation climb, which suggests a means of controlling microstructures and properties of nanostructured metals.

Atomic Scale Characterization of Oxygen Vacancy Segregation at SrTiO3 Grain Boundaries

2000 ◽  
Vol 654 ◽  
Author(s):  
R.F. Klie ◽  
N. D. Browning
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Oxygen Vacancies ◽  
Elevated Temperatures ◽  
Theoretical Models ◽  
Atomic Scale ◽  
Close Proximity ◽  
Scale Characterization

AbstractWe have examined the structure, composition and bonding at an un-doped 58° [001] tilt grain-boundary in SrTiO3 in order to investigate the control that the grain boundary exerts over the bulk properties. Room temperature and in-situ heating experiments show that there is a segregation of oxygen vacancies to the grain boundary that is increased at elevated temperatures and is independent of the cation arrangement. These measurements indicate that the widely observed electronic properties of grain boundaries may be due to an excess of mobile oxygen vacancies that cause a highly doped n-type region in the close proximity ( ≍ 1 unit cell) to the boundary. These results are shown to be consistent with both theoretical models and lower resolution chemical analysis.

Dislocation–grain boundary interactions in martensitic steel observed through in situ nanoindentation in a transmission electron microscope

2004 ◽  
Vol 19 (12) ◽  
pp. 3626-3632 ◽  
Author(s):  
T. Ohmura ◽  
A.M. Minor ◽  
E.A. Stach ◽  
J.W. Morris
Keyword(s):  
Electron Microscope ◽  
Grain Boundary ◽  
Transmission Electron Microscope ◽  
Critical Stress ◽  
Martensitic Steel ◽  
High Angle ◽  
Block Boundary ◽  
Density Of Dislocations ◽  
Transmission Electron

Dislocation–interface interactions in Fe–0.4 wt% C tempered martensitic steel were studied through in situ nanoindentation in a transmission electron microscope (TEM). Two types of boundaries were imaged in the dislocated martensitic structure: a low-angle (probable) lath boundary and a coherent, high-angle (probable) block boundary. In the case of a low-angle grain boundary, the dislocations induced by the indenter piled up against the boundary. As the indenter penetrated further, a critical stress appeared to have been reached, and a high density of dislocations was suddenly emitted on the far side of the grain boundary into the adjacent grain. In the case of the high-angle grain boundary, the numerous dislocations that were produced by the indentation were simply absorbed into the boundary, with no indication of pileup or the transmission of strain. This surprising observation is interpreted on the basis of the crystallography of the block boundary.

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