ECCI Observation of Dislocation Structure Formed around an Intergranular Fatigue Crack in Copper

2007 ◽  
pp. 1317-1320
Author(s):  
Yoshihisa Kaneko ◽  
M. Ishikawa ◽  
Satoshi Hashimoto
Keyword(s):  
Fatigue Crack ◽  
Dislocation Structure

Dislocation structure and fatigue crack growth in titanium alloy VT5-1ct at temperatures of 293-11 K

1993 ◽  
Vol 165 (2) ◽  
pp. 125-131 ◽  
Author(s):  
N.M. Grinberg ◽  
A.R. Smirnov ◽  
V.A. Moskalenko ◽  
E.N. Aleksenko ◽  
L.F. Yakovenko ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Dislocation Structure

scholarly journals Evolution of Dislocation Structure and Fatigue Crack Behavior in Fe–Si Alloys during Cyclic Bending Test

2009 ◽  
Vol 49 (2) ◽  
pp. 312-321 ◽  
Author(s):  
Kohsaku Ushioda ◽  
Shoji Goto ◽  
Yoshinari Komatsu ◽  
Akinori Hoshino ◽  
Shigeto Takebayashi
Keyword(s):  
Fatigue Crack ◽  
Dislocation Structure ◽  
Bending Test ◽  
Cyclic Bending ◽  
Crack Behavior

scholarly journals Evolution of Dislocation Structure and Fatigue Crack Behavior in Fe-Si Alloys during Cyclic Bending Test

2008 ◽  
Vol 94 (8) ◽  
pp. 321-330 ◽  
Author(s):  
Kohsaku Ushioda ◽  
Shoji Goto ◽  
Yoshinari Komatsu ◽  
Akinori Hoshino ◽  
Shigeto Takebayashi
Keyword(s):  
Fatigue Crack ◽  
Dislocation Structure ◽  
Bending Test ◽  
Cyclic Bending ◽  
Crack Behavior

A method to predict fatigue crack initiation in metals using dislocation dynamics

2017 ◽  
Vol 35 (4-5) ◽  
pp. 325-341 ◽  
Author(s):  
Christian Heinrich ◽  
Veera Sundararaghavan
Keyword(s):  
Fatigue Crack ◽  
Dislocation Density ◽  
Crack Initiation ◽  
Gibbs Energy ◽  
Dislocation Structure ◽  
Fatigue Cracks ◽  
Fatigue Crack Initiation ◽  
Dislocation Dynamics ◽  
Continuum Energy ◽  
Number Of Cycles

AbstractA theory is proposed to predict the initiation of fatigue cracks using cyclic dislocation dynamics (DD) simulations. The evolution of dislocation networks in a grain is simulated over several cycles. It is shown that the dislocation density and the energy stored in the dislocation networks increase with the number of cycles. The results of the DD simulations are used to construct an energy balance expression for crack initiation. A hypothetical crack is inserted into the grain, and the Gibbs energy consisting of the energy of the dislocation structure, the surface energy of the hypothetical crack, and the reduction in continuum energy is evaluated. Once the Gibbs energy attains a maximum, the dislocation structure becomes unstable, and it becomes energetically more favorable to form a real crack. The proposed method is applied to oxygen-free high conductivity copper, and the results are compared against experiments. Finally, it is shown how the method can be amended to account for environmental effects.

scholarly journals Evolution of dislocation structure and fatigue crack behavior in Fe-Si alloys during cyclic bending test

2010 ◽  
Vol 240 ◽  
pp. 012041 ◽  
Author(s):  
Kohsaku Ushioda ◽  
Shoji Goto ◽  
Yoshinari Komatsu ◽  
Akinori Hoshino ◽  
Shigeto Takebayashi
Keyword(s):  
Fatigue Crack ◽  
Dislocation Structure ◽  
Bending Test ◽  
Cyclic Bending ◽  
Crack Behavior

ECCI Observation of Dislocation Structure Formed around an Intergranular Fatigue Crack in Copper

2007 ◽  
Vol 26-28 ◽  
pp. 1317-1320
Author(s):  
Yoshihisa Kaneko ◽  
M. Ishikawa ◽  
Satoshi Hashimoto
Keyword(s):  
Fatigue Crack ◽  
Grain Boundaries ◽  
Dislocation Structure ◽  
Polycrystalline Copper ◽  
Contrast Imaging ◽  
Slip Bands ◽  
Copper Specimen ◽  
Cell Structures ◽  
Electron Channelling ◽  
Fatigue Crack Growth Test

A fatigue crack growth test was conducted in a polycrystalline copper. Dislocation structure formed near an intergranular fatigue crack was investigated by electron channelling contrast imaging (ECCI) method. The ECCI method enables us to observe dislocations lying under surface using a scanning electron microscope. The fatigue crack in the copper specimen was grown along both grain boundaries and slip bands inside grain. The ECCI observations revealed that both the vein dislocation structure and the cell structures were formed near the grain boundaries. The formations of different dislocation structures near boundaries could be interpreted in terms of the plastic strain incompatibility.

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