The Thermodynamics of Thermally-Activated Dislocation Glide

1965 ◽  
Vol 10 (2) ◽  
pp. 507-512 ◽  
Author(s):  
G. B. Gibbs
Keyword(s):  
Dislocation Glide ◽  
Thermally Activated

Deformation Modeling Applied to Stress Relaxation of Four Solder Alloys

1980 ◽  
Vol 102 (2) ◽  
pp. 207-214 ◽  
Author(s):  
R. W. Rohde ◽  
J. C. Swearengen
Keyword(s):  
Stress Relaxation ◽  
Stainless Steels ◽  
General Concept ◽  
Model Parameters ◽  
Recovery Model ◽  
Solder Alloys ◽  
Dislocation Glide ◽  
Thermally Activated ◽  
Dependent Behavior ◽  
Excellent Description

Stress relaxation of four solder alloys, 50 percent Pb-50 percent In; 37.5 percent Sn-37.5 percent Pb-25 percent In; 63 percent Sn-37 percent Pb; and 62.5 percent Sn-37 percent Pb-0.5 percent Ag, has been examined at 222 K, 298 K, and 344 K. A model previously utilized to describe inelastic deformation of aluminum and stainless steels is applied and found to provide an excellent description of the experimental data. This model is based upon the general concept of stress assisted thermally activated dislocation glide in a microstructure evolving by the process of strain hardening and recovery. Model parameters useful for calculations of time dependent behavior of these solders are presented and their significance is discussed.

Modeling of Dislocation Mobility in Metals: Effect of Obstacles and Thermal Processes

2001 ◽  
Vol 683 ◽  
Author(s):  
Masato Hiratani ◽  
Hussein M. Zbib
Keyword(s):  
Thermal Activation ◽  
Dislocation Dynamics ◽  
Thermal Processes ◽  
Weak Point ◽  
Dislocation Glide ◽  
Thermally Activated ◽  
Discrete Dislocation Dynamics ◽  
Discrete Dislocation ◽  
Activation Rate ◽  
Activation Event

ABSTRACTThermally activated dislocation glide velocity through weak point obstacle arrays is studied analytically and computationally. Thermal activation rate is estimated using the modified Friedel relations under the weak obstacle approximation. The average flight velocity after an activation event as a function of stress and temperature is obtained by the discrete dislocation dynamics (DD). This numerical calculation includes the effect of self-stress, interaction with electrons and phonons, and the inertial effect. These results are implemented into a phenomenological model to study the dislocation velocity under various conditions. The model can reproduce both obstacle control and drag control motion in low and high velocity regions, and a flow stress anomaly at transient regions.

scholarly journals Temperature dependence of mechanical properties in ultrathin Au films with and without passivation

2008 ◽  
Vol 23 (9) ◽  
pp. 2406-2419 ◽  
Author(s):  
Patric A. Gruber ◽  
Sven Olliges ◽  
Eduard Arzt ◽  
Ralph Spolenak
Keyword(s):  
Mechanical Properties ◽  
Temperature Dependence ◽  
Elevated Temperatures ◽  
Bulk Material ◽  
Diffusional Creep ◽  
Strong Temperature Dependence ◽  
Metallic Films ◽  
Dislocation Glide ◽  
Thermally Activated ◽  
Passivation Layers

Temperature and film thickness are expected to have an influence on the mechanical properties of thin films. However, mechanical testing of ultrathin metallic films at elevated temperatures is difficult, and few experiments have been conducted to date. Here, we present a systematic study of the mechanical properties of 80–500-nm-thick polycrystalline Au films with and without SiNx passivation layers in the temperature range from 123 to 473 K. The films were tested by a novel synchrotron-based tensile testing technique. Pure Au films showed strong temperature dependence above 373 K, which may be explained by diffusional creep. In contrast, passivated samples appeared to deform by thermally activated dislocation glide. The observed activation energies for both mechanisms are considerably lower than those for the bulk material, indicating that concomitant stress relaxation mechanisms are more pronounced in the thin film geometry.

Line width Dependence of Stress Relaxation and Yield Behavior of Passivated Al(Cu) Lines

1994 ◽  
Vol 338 ◽  
Author(s):  
I.-S. Yeo ◽  
S.G.H. Anderson ◽  
C.-N. Liao ◽  
D. Jawarani ◽  
H. Kawasaki ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Void Formation ◽  
Relaxation Behavior ◽  
Effect Of Temperature ◽  
Thermally Induced ◽  
Stress Relaxation Behavior ◽  
Cu Films ◽  
Dislocation Glide ◽  
Thermally Activated ◽  
On Line

ABSTRACTStress relaxation behavior of thermally induced stresses in passivated line structures is strongly influenced by the metal yield strength. For some line geometries, stress relaxation can lead to void formation. In this study, bending beam measurements have been carried out to measure the thermal stress and stress relaxation behavior of passivated Al(l wt.% Cu) line structures with 3, 1, and 0.5 µm line widths. Our results reveal that stress relaxation in Al(Cu) films and lines shows log(time) kinetics consistent with a thermally activated dislocation glide mechanism. The kinetics of stress relaxation depend on line geometry and temperature, which can be explained by a combined effect of temperature (mass transport) and shear stress (driving force).

Bulk Mechanical Properties Of Quasicrystals

1998 ◽  
Vol 553 ◽  
Author(s):  
S. Takeuchi
Keyword(s):  
Deformation Behavior ◽  
Strain Field ◽  
Elastic Moduli ◽  
Controlling Factors ◽  
Plastic Behavior ◽  
Dislocation Mechanism ◽  
Dislocation Glide ◽  
Thermally Activated ◽  
Decagonal Quasicrystals ◽  
Plastic Deformation Behavior

AbstractElastic moduli, anharmonicity, hardness and high temperature plastic behavior of icosahedral and decagonal quasicrystals are reviewed. Elastic properties are discussed in relation to the bonding nature of the quasicrystals. The plastic deformation behavior at high temperatures is discussed based on the characteristics of the dislocation mechanism in the quasiperiodic lattice. A Peierls potential, a phason relaxation and a dragging stress due to production of a defect field are considered as the controlling factors for the thermally activated dislocation glide; a dislocation in quasiperiodic lattice is accompanied not only by the elastic (phonon) strain field but also by the phason strain field which is difficult to be relaxed completely with the dislocation glide.

Sign in / Sign up

Export Citation Format

Share Document