scholarly journals Effect of stacking fault tetrahedron on spallation of irradiated Cu via molecular dynamics study

2020 ◽  
Vol 69 (3) ◽  
pp. 036201
Author(s):  
Qi Zhu ◽  
Sheng-Tao Wang ◽  
Fu-Qi Zhao ◽  
Hao Pan
2007 ◽  
Vol 22 (10) ◽  
pp. 2758-2769 ◽  
Author(s):  
Hyon-Jee Lee ◽  
Jae-Hyeok Shim ◽  
Brian D. Wirth

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.


2017 ◽  
Vol 136 ◽  
pp. 78-82 ◽  
Author(s):  
Liang Zhang ◽  
Cheng Lu ◽  
Guillaume Michal ◽  
Guanyu Deng ◽  
Kiet Tieu

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1278
Author(s):  
Jianhua Li ◽  
Ruicheng Feng ◽  
Haiyang Qiao ◽  
Haiyan Li ◽  
Maomao Wang ◽  
...  

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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