scholarly journals The Role of Dislocation Climb in the High Temperature Deformation of Mg alloys AZ31B and ZK10 and the Distinctions in the Activity of Dislocations with a c-type Burgers Vector

2021 ◽  
Author(s):  
Michael Ritzo ◽  
Sean Agnew
Keyword(s):  
High Temperature ◽  
Dislocation Climb ◽  
Mg Alloys ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Burgers Vector

Estimation of Back Stress Produced by Dislocation Interaction in Icosahedral Al-Pd-Mn

2000 ◽  
Vol 643 ◽  
Author(s):  
Hisatoshi Hirai ◽  
Akira Kitahara ◽  
Fuyuki Yoshida ◽  
Hideharu Nakashima
Keyword(s):  
Shear Stress ◽  
High Temperature ◽  
Main Part ◽  
Unit Length ◽  
Back Stress ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Dislocation Interaction ◽  
Burgers Vector ◽  
Phonon Component

AbstractWe attempted to calculate the breakaway stress σb of dislocation from attractive junction made by reaction of dislocations. Assuming that the force f acting on the unit length of dislocation with the Burgers vector B under a shear stress τa is f τ∣b˝∣ where b˝ is the phonon component of B, and that the elastic energy per unit length of dislocation W is approximated by W = G(∣b˝∣2 + c2 ∣b˔∣2) where G is the shear modulus, b˔ the phason component of B and c2 a coefficient of about 3.1 × 10−3. Using the values G = 48.4 GPa at 1070 K, the Taylor factor M = 3 and the measured dislocation density of 1.8 × 1013 m−2, we calculated σb for 21 possible dislocation reactions. Picking up the most possible dislocation reactions, σb distributed between 50 and 80 MPa, and the average of them was 64 MPa. This result strongly suggested the possibility that the main part of the internal stress of the high-temperature deformation of icosahedral Al-Pd-Mn is explained by σb.

Modelling Dynamic Recovery and Recrystallization of Metals by a New Non-Equilibrium Thermodynamics Approach

2007 ◽  
Vol 558-559 ◽  
pp. 517-522
Author(s):  
Ming Xin Huang ◽  
Pedro E.J. Rivera-Díaz-del-Castillo ◽  
Sybrand van der Zwaag
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Flow Stress ◽  
Dislocation Density ◽  
Dynamic Recovery ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Equilibrium Thermodynamics ◽  
Burgers Vector ◽  
Non Equilibrium

A non-equilibrium thermodynamics-based approach is proposed to predict the dislocation density and flow stress at the steady state of high temperature deformation. For a material undergoing dynamic recovery and recrystallization, it is found that the total dislocation density can be expressed as ( )2 ρ = λε& b , where ε& is the strain rate, b is the magnitude of the Burgers vector and λ is a dynamic recovery and recrystallization related parameter.

The role of interphase boundary phenomena on mechanical behavior during high-temperature deformation

1991 ◽  
Vol 49 ◽  
pp. 594-595
Author(s):  
B. Hidalgo-Prada
Keyword(s):  
High Temperature ◽  
Mechanical Behavior ◽  
Interphase Boundary ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Metallographic Analysis ◽  
Two Phase ◽  
Transmission Electron ◽  
Phase Size

The influence of interphase boundary on the mechanical behavior of a two-phase (α/β) Ni-Modified Ti-6A1-4V alloy during superplastic deformation (SPD), has been investigated in the range of temperature and strain rate where maximum ductility is - attained.Uniaxial tests for constant and differential strain rates were performed over the - range of 5.0 x 10-5 s-1 to 5.0 x 10-3 s-1 and at temperature from 1023 to 1123 K. To optimize the initial microstructure, tensile specimens were static annealed in argon for 1 hour at 815 °C ( SA-1-815).Upon completion of the tests, specimens were quenched in pre-chilled argon to pre—serve the high temperature microstructure for metallographic analysis. The gage portion of the specimen was polished and etched in a solution of 2 ml HF, 3 ml HNO3 and 95 ml H2O. Subsequently, they were subjected to scanning and transmission electron - microscopy (SEM and TEM) examination. A Quantimet Image Analizer was used for determining the phase size, its distribution and volume fractions.

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