The formation and destruction of stacking fault tetrahedron in fcc metals: A molecular dynamics study

2017 ◽  
Vol 136 ◽  
pp. 78-82 ◽  
Author(s):  
Liang Zhang ◽  
Cheng Lu ◽  
Guillaume Michal ◽  
Guanyu Deng ◽  
Kiet Tieu
Keyword(s):  
Molecular Dynamics ◽  
Stacking Fault ◽  
Fcc Metals ◽  
Stacking Fault Tetrahedron

Molecular Dynamics Simulations to Evaluate the Effect of the Difference in Material Properties on Irradiation-Induced Defect Formation Under Applied Strain

2012 ◽  
Author(s):  
Toshihiro Horinouchi ◽  
Satoshi Miyashiro ◽  
Mitsuhiro Itakura ◽  
Taira Okita
Keyword(s):  
Molecular Dynamics ◽  
Defect Formation ◽  
Stacking Fault ◽  
Applied Strain ◽  
Stacking Fault Energy ◽  
Cascade Process ◽  
Defect Production ◽  
Fcc Metals ◽  
The Difference ◽  
Dynamics Simulations

The influence of applied strain on the defect production rate during a cascade process was evaluated for several FCC metals with different Stacking Fault Energy by the method of molecular dynamics. It was found that applied strain increases the number of surviving defects, which is caused by the enhanced formation of larger clusters. It was also found that the number of defects is almost independent of Stacking Fault Energy even under applied strain.

Molecular dynamics simulation of screw dislocation interaction with stacking fault tetrahedron in face-centered cubic Cu

2007 ◽  
Vol 22 (10) ◽  
pp. 2758-2769 ◽  
Author(s):  
Hyon-Jee Lee ◽  
Jae-Hyeok Shim ◽  
Brian D. Wirth
Keyword(s):  
Molecular Dynamics ◽  
Screw Dislocation ◽  
Stacking Fault ◽  
Dynamics Simulation ◽  
Face Centered Cubic ◽  
Dislocation Interaction ◽  
Complete Absorption ◽  
Stacking Fault Tetrahedron ◽  
Face Centered ◽  
Dynamics Simulations

The interaction of a gliding screw dislocation with stacking fault tetrahedron (SFT) in face-centered cubic (fcc) copper (Cu) was studied using molecular dynamics simulations. Upon intersection, the screw dislocation spontaneously cross slips on the SFT face. One of the cross-slipped Shockley partials glides toward the SFT base, partially absorbing the SFT. At low applied stress, partial absorption produces a superjog, with detachment of the trailing Shockley partial via an Orowan process. This leaves a small perfect SFT and a truncated base behind, which subsequently form a sheared SFT with a pair of opposite sense ledges. At higher applied shear stress, the ledges can self-heal by gliding toward an SFT apex and transform the sheared SFT into a perfect SFT. However, complete absorption or collapse of an SFT (or sheared SFT) by a moving screw dislocation is not observed. These observations provide insights into defect-free channel formation in deformed irradiated Cu.

scholarly journals Effect of Cutting Crystal Directions on Micro-Defect Evolution of Single Crystal γ-TiAl Alloy with Molecular Dynamics Simulation

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1278
Author(s):  
Jianhua Li ◽  
Ruicheng Feng ◽  
Haiyang Qiao ◽  
Haiyan Li ◽  
Maomao Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Single Crystal ◽  
Dislocation Loop ◽  
Tial Alloy ◽  
Amorphous Layer ◽  
Stacking Fault ◽  
Dynamics Simulation ◽  
Machined Surface ◽  
Stacking Fault Tetrahedron

In this work, the distribution and evolution of micro-defect in single crystal γ-TiAl alloy during nanometer cutting is studied by means of molecular dynamics simulation. Nanometer cutting is performed along two typical crystal directions: [ 1 ¯ 00 ] and [ 1 ¯ 01 ] . A machined surface, system potential energy, amorphous layer, lattice deformation and the formation mechanism of chip are discussed. The results indicate that the intrinsic stacking fault, dislocation loop and atomic cluster are generated below the machined surface along the cutting crystal directions. In particular, the Stacking Fault Tetrahedron (SFT) is generated inside the workpiece when the cutting crystal direction is along [ 1 ¯ 00 ] . However, a “V”-shape dislocation loop is formed in the workpiece along [ 1 ¯ 01 ] . Furthermore, atomic distribution of the machined surface indicates that the surface quality along [ 1 ¯ 00 ] is better than that along [ 1 ¯ 01 ] . In a certain range, the thickness of the amorphous layer increases gradually with the rise of cutting force during nanometric cutting process.

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