Constitutive modeling for strain rate-dependent behaviors of nanocrystalline materials based on dislocation density evolution and strain gradient

2014 ◽  
Vol 29 (24) ◽  
pp. 2982-2993 ◽  
Author(s):  
Youyi Wu ◽  
Jianqiu Zhou ◽  
Shuhong Dong ◽  
Aosheng Hu ◽  
Lu Wang ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Strain Rate ◽  
Strain Gradient ◽  
Constitutive Modeling ◽  
Nanocrystalline Materials ◽  
Density Evolution ◽  
Rate Dependent ◽  
Image Position

Abstract

Geometrically necessary dislocation density evolution as a function of microstructure and strain rate

2021 ◽  
pp. 142224
Author(s):  
Daniel L. Foley ◽  
Marat I. Latypov ◽  
Xingyuan Zhao ◽  
Jonathan Hestroffer ◽  
Irene J. Beyerlein ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Strain Rate ◽  
Density Evolution ◽  
Geometrically Necessary Dislocation

Observations of dislocation interactions with recrystallized grain boundaries

1988 ◽  
Vol 46 ◽  
pp. 628-629
Author(s):  
C. W. Price
Keyword(s):  
Dislocation Density ◽  
Grain Boundary ◽  
Strain Rate ◽  
Grain Boundaries ◽  
Dislocation Structure ◽  
Hot Deformation ◽  
Static Recrystallization ◽  
High Dislocation Density ◽  
High Angle ◽  
Dislocation Interactions

Little evidence exists on the interaction of individual dislocations with recrystallized grain boundaries, primarily because of the severely overlapping contrast of the high dislocation density usually present during recrystallization. Interesting evidence of such interaction, Fig. 1, was discovered during examination of some old work on the hot deformation of Al-4.64 Cu. The specimen was deformed in a programmable thermomechanical instrument at 527 C and a strain rate of 25 cm/cm/s to a strain of 0.7. Static recrystallization occurred during a post anneal of 23 s also at 527 C. The figure shows evidence of dissociation of a subboundary at an intersection with a recrystallized high-angle grain boundary. At least one set of dislocations appears to be out of contrast in Fig. 1, and a grainboundary precipitate also is visible. Unfortunately, only subgrain sizes were of interest at the time the micrograph was recorded, and no attempt was made to analyze the dislocation structure.

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