Modeling of abnormal mechanical properties of nickel-based single crystal superalloy by three-dimensional discrete dislocation dynamics

2014 ◽  
Vol 22 (8) ◽  
pp. 085009 ◽  
Author(s):  
Hui Yang ◽  
Zhenhuan Li ◽  
Minsheng Huang
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Three Dimensional ◽  
Dislocation Dynamics ◽  
Single Crystal Superalloy ◽  
Discrete Dislocation Dynamics ◽  
Discrete Dislocation

Influence of Initial Defects on the Mechanical Properties of Single Crystal Copper: Discrete Dislocation Dynamics Study

2018 ◽  
Vol 913 ◽  
pp. 627-635
Author(s):  
Ming Yi Zhang ◽  
Min Zhong ◽  
Shuai Yuan ◽  
Jing Song Bai ◽  
Ping Li
Keyword(s):  
Dislocation Density ◽  
Single Crystal ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Dislocation Dynamics ◽  
Single Crystal Copper ◽  
Discrete Dislocation Dynamics ◽  
Discrete Dislocation ◽  
Stress Curve ◽  
Initial Dislocation Density

In this paper, three dimensional discrete dislocation dynamics method was used to quantitatively investigate the influence of initial defects on mechanical response of single crystal copper. Both the irradiation defects (interstitial loops) and random dislocation lines with different densities are considered. The simulation results demonstrate that the yield strength of single crystal copper is higher with higher initial dislocation density and higher interstitial loop density. Dislocation density increases quickly by nucleation and multiplication and microbands are formed during plastic deformation when only the random dislocation lines are initially considered. Characteristics of microbands show excellent agreement with experiment results. Dislocation multiplication is suppressed in the presence of interstitial loops, and junctions and locks between dislocations and interstitial loops are formed. Dislocation density evolution shows fluctuation accompanied with strain-stress curve fluctuation.

3D Discrete Dislocation Models Of Thin-Film Plasticity

1997 ◽  
Vol 505 ◽  
Author(s):  
A. Hartmaier ◽  
M. C. Fivel ◽  
G. R. Canova ◽  
P. Gumbsch
Keyword(s):  
Thin Film ◽  
Three Dimensional ◽  
Dislocation Dynamics ◽  
Normal Stresses ◽  
Bulk Materials ◽  
Free Standing ◽  
Discrete Dislocation Dynamics ◽  
Discrete Dislocation ◽  
Dislocation Models ◽  
Dimensional Simulation

ABSTRACTThree-dimensional simulation schemes for discrete dislocation dynamics (DDD) have been used successfully to investigate plasticity of bulk materials. The adaptation of these DDD schemes to a description of thin-film plasticity requires detailed modeling of the interfaces and surfaces of the film. One possible method is to compensate for the normal stresses that a dislocation distribution exerts on a surface by appropriate point loads. This traction-compensation method is extended to a free standing film (two opposing surfaces). The extension to a thin film on a substrate is possible.

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