Internal stress and thermally activated dislocation motion in an AZ63 magnesium alloy

Published on Nov 1, 2011in Materials Chemistry and Physics4.094
· DOI :10.1016/J.MATCHEMPHYS.2011.08.045
Zuzanka Trojanová20
Estimated H-index: 20
(Charles University in Prague),
Kristián Máthis19
Estimated H-index: 19
(Charles University in Prague)
+ 2 AuthorsFrantišek Chmelík28
Estimated H-index: 28
(Charles University in Prague)
Sources
Abstract
Abstract Magnesium alloy AZ63 was deformed at temperatures between room temperature and 300 °C. Stress relaxation tests were performed in order to reveal the physical base of the deformation process/-es. Internal and effective components of the applied stress have been estimated. Very high values of the internal stress estimated at room temperature decrease rapidly with increasing deformation temperature. The apparent activation volume decreases with increasing effective stress. Estimated values of the activation volume as well as the activation enthalpy indicate that the main thermally activated process is connected with the rapid decrease of the internal stress.
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References26
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#1Daniel CaillardH-Index: 34
#2Jean-Luc MartinH-Index: 18
Experimental Charecterization of Dislocation Mechanisms, Interactions Between Dislocations and Small-size Obstacles, Frictional Forces in Metals, Dislocation Cross-slip, Experimental Studies of Peierls-Naborro-Type Friction Forces in Metals and Alloys, The Peierl-Nabarro Mechanisms in Covalent Crystals, Dislocations Climb, Dislocation Multiplication, Exhaustion and Work Hardening, Mechanical Behaviour of some ordered intermetallic
#1Pavel LukáčH-Index: 31
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Stress relaxation tests along stress-strain curves of two magnesium alloys AJ51 and AE42 are used for determining the activation volume at different test temperatures. The applied stress has been separated into its effective stress and internal stress components. The variations of the activation volumes with the effective stress are examined.
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Magnesium alloys of AJ (Mg-Al-Sr) and AX (Mg-Al-Ca) series were deformed at temperatures between room temperature and 300°C. Stress relaxation tests were performed in order to reveal features of the thermally activated dislocation motion. The work hardening rate 0 = dσ/de decreases with increasing stress and temperature. Analysis of the θ-σ plots revealed the hardening and softening mechanisms operating during the deformation. Internal and effective components of the applied stress have been est...
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