A Method to Determine the Internal Stress and the Stress Exponent m of the Dislocation Velocity

1990 ◽  
Vol 120 (1) ◽  
pp. K19-K23 ◽  
Author(s):  
M. Tanibayashi
Keyword(s):  
Internal Stress ◽  
Stress Exponent ◽  
Dislocation Velocity

Determination of the internal stress and dislocation velocity stress exponent with indentation stress relaxation test

2008 ◽  
Vol 23 (9) ◽  
pp. 2486-2490 ◽  
Author(s):  
B.X. Xu ◽  
X.M. Wang ◽  
Z.F. Yue
Keyword(s):  
Stress Relaxation ◽  
Internal Stress ◽  
Stress Exponent ◽  
Indentation Test ◽  
Dislocation Velocity ◽  
Attractive Potential ◽  
Integral Constant ◽  
Properties Of Materials ◽  
Relaxation Curves

Indentation stress relaxation tests were carried out on high-purity polycrystalline copper specimens at room temperature with a flat cylindrical indenter. The experimental results showed that the resulting load-time relaxation curves can be described by a power law, which coupled an internal stress and an integral constant between the effective stress and relaxation time. Then the internal stress, integral constant, and dislocation velocity stress exponent can be extracted from load relaxation curves. The derived values from this way were consistent with the results of conventional uniaxial compression stress relaxation tests. These agreements are not only useful to understand deformation (dislocation) mechanisms under the indenter, but also exhibit an attractive potential of measuring nano/micromechanical properties of materials by indentation test.

An Interpretation of the Dislocation Velocity-Stress Exponent

1967 ◽  
Vol 22 (2) ◽  
pp. 607-616 ◽  
Author(s):  
K. R. Evans ◽  
D. J. Bailey ◽  
W. F. Flanagan
Keyword(s):  
Stress Exponent ◽  
Dislocation Velocity

Deformation Behavior And Internal Stress Of Icosahedral Al-Pd-Mn With Decagonal Phase Lamellae At Elevated Temperatures

1998 ◽  
Vol 553 ◽  
Author(s):  
H. Hirai ◽  
T. Tomita ◽  
F. Yoshida ◽  
H. Nakashima
Keyword(s):  
Stress Relaxation ◽  
Strain Rate ◽  
Internal Stress ◽  
Stress Exponent ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Initial Strain Rate ◽  
Decagonal Phase ◽  
Thermally Activated ◽  
High Internal Stress

AbstractFine decagonal phase lamellae-bearing icosahedral Al-Pd-Mn quasicrystals were tested compressionally at temperatures of 997 to 1073 K and initial strain rate of 3 × 10−5. to I × 10−4 S−1, and stress relaxation tests were performed at various stages of deformation. The results confirmed the thermally activated nature of deformation, and the stress exponent of strain rate was around 4. Internal stress for deformation estimated by Kikuchi's method reached 50 to 90 % of applied stress. The effective stress exponent of strain rate was revealed to be about 1.3. At least a part of high internal stress was attributable to complicated dislocation microstructure.

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