scholarly journals Dislocation Cross-Slip in Nanocrystalline fcc Metals

2008 ◽  
Vol 100 (23) ◽  
Author(s):  
E. Bitzek ◽  
C. Brandl ◽  
P. M. Derlet ◽  
H. Van Swygenhoven
Keyword(s):  
Cross Slip ◽  
Fcc Metals

Dislocation-mediated Mechanisms of Mass Transport around Nanoindentations in Fcc Metals

2002 ◽  
Vol 738 ◽  
Author(s):  
Oscar Rodríguez de la Fuente ◽  
Esther Carrasco ◽  
Miguel A. González ◽  
Juan M. Rojo
Keyword(s):  
Mass Transport ◽  
Surface Diffusion ◽  
Dislocation Motion ◽  
Cross Slip ◽  
Dislocation Theory ◽  
Present Evidence ◽  
Fcc Metals

ABSTRACTWe present evidence for the operation on reconstructed Au(001) of a novel mechanism, involving dislocation motion, which is much more efficient than surface diffusion to redistribute mass around nanoindentations. Cross-slip of individual dislocations generated around the indentation point, with a screw component perpendicular to the surface, is shown to be responsible for the generation of multiple-storied, crystallographically-oriented terraces around the nanoindentation points. We also show that standard dislocation theory can be used to quantitatively describe the characteristics of the dislocations involved in the different processes around the nanoindentation.

The Role of Stacking Fault Energy on the Indentation Size Effect of FCC Pure Metals and Alloys

2012 ◽  
Vol 1424 ◽  
Author(s):  
D.E. Stegall ◽  
M.A. Mamun ◽  
A.A. Elmustafa
Keyword(s):  
Size Effect ◽  
Indentation Size Effect ◽  
Stacking Fault ◽  
Cross Slip ◽  
Indentation Size ◽  
Fcc Metals ◽  
Partial Dislocations ◽  
Dislocation Movement ◽  
Pure Metals ◽  
Interfacial Characteristic

ABSTRACTWe investigated the effect of stacking fault free energy (SFE), on the magnitude of the indentation size effect (ISE) of several pure FCC metals using nanoindentation. The metals chosen were 99.999% Aluminum, 99.95% Nickel, 99.95% Silver, and 70/30 Copper Zinc (α-brass). Aluminum has a high SFE of about 200 mJ/ m2, whereas α -brass has a low SFE of less than 10 mJ/ m2. Nickel and Silver have intermediate SFE of about 128 mJ/ m2 and 22 mJ/m2 respectively. The SFE is an important interfacial characteristic and plays a significant role in the deformation of FCC metals due to its influence on dislocation movement and morphology. The SFE is a measure of the distance between partial dislocations and has a direct impact on the ability of dislocations to cross slip during plastic deformation. The lower the SFE the larger the separation between partial dislocations and thus cross slip and dynamic recovery are inhibited. The SFE impacts pure metals differently from alloys. It was discovered that the characteristic ISE behavior for the pure metals was different when compared to the α-brass which is an alloy. Several additional alloys were chosen for comparison including 7075 Aluminum and 70/30 Nickel Copper.

Are rate sensitivity and strength effected by cross-slip in nano-twinned fcc metals

2008 ◽  
Vol 58 (5) ◽  
pp. 389-392 ◽  
Author(s):  
Robert J Asaro ◽  
Yashashree Kulkarni
Keyword(s):  
Rate Sensitivity ◽  
Cross Slip ◽  
Fcc Metals

Calculations of intersection cross-slip activation energies in fcc metals using nudged elastic band method

2011 ◽  
Vol 59 (19) ◽  
pp. 7135-7144 ◽  
Author(s):  
S.I. Rao ◽  
D.M. Dimiduk ◽  
T.A. Parthasarathy ◽  
J. El-Awady ◽  
C. Woodward ◽  
...  
Keyword(s):  
Activation Energies ◽  
Cross Slip ◽  
Elastic Band ◽  
Fcc Metals ◽  
Band Method

Stochastic Dislocation Dynamics under Creep Conditions in Metals

2002 ◽  
Vol 731 ◽  
Author(s):  
Masato Hiratani ◽  
Hussein M. Zbib
Keyword(s):  
Thermal Fluctuation ◽  
Dislocation Motion ◽  
Cross Slip ◽  
Dislocation Dynamics ◽  
Atomistic Simulations ◽  
Thermal Processes ◽  
New Model ◽  
Slip Mechanism ◽  
Fcc Metals ◽  
Thermally Activated

AbstractA stochastic model is proposed to study dislocation dynamics in metallic single crystals. A Langevin type thermal fluctuation is taken into account for the model to maintain thermal equilibrium. This approach works as Brownian motion of segmental dislocations. Additionally, a new model for implementing the cross slip mechanism in FCC metals is developed based on results obtained by atomistic simulations. This new model is capable of simulating realistic thermal processes such as thermally activated dislocation motion during easy glide or cross slip during cold working of metals.

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