Stress Relaxation in an AZ31 Magnesium Alloy

Published on Jan 1, 2011in Key Engineering Materials
· DOI :10.4028/WWW.SCIENTIFIC.NET/KEM.465.101
Pavel Lukáč31
Estimated H-index: 31
(Charles University in Prague),
Zuzanka Trojanová20
Estimated H-index: 20
(Charles University in Prague)
Stress relaxation tests have been used in order to determine parameters of a possible thermally activated process in AZ31 magnesium alloy. The samples were deformed at a constant initial strain rate of 6.7x10-5 s-1 at various temperatures between room temperature and 300 °C. Stress relaxation, i.e. a decrease in the stress with time, was measured at various stress levels and at various temperatures. An analysis of the stress relaxation curves enabled to estimate the internal stress as a function of the strain and the test temperature. It has been shown that the activation volume is a function of the effective stress independently of the deformation temperature.
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Cited By3
Last. Sean R. AgnewH-Index: 55
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#1Vikaas Bajikar (UVA: University of Virginia)H-Index: 1
#2Jishnu J. Bhattacharyya (UVA: University of Virginia)H-Index: 12
Last. Sean R. Agnew (UVA: University of Virginia)H-Index: 55
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It is of interest to assess the thermally activated nature of the deformation mechanisms responsible for the anisotropic response of textured Mg alloys, especially in those alloys that do and do not contain rare earth elements. The repeated stress relaxation method in combination with elasto-viscoplastic self-consistent (EVPSC) polycrystal modeling is employed to determine the strain rate sensitivity and true activation volume of samples of textured, polycrystalline Mg alloys, ME10 and AZ31, loa...
#1W Tang (UIUC: University of Illinois at Urbana–Champaign)H-Index: 1
#2K. L. Halm (UIUC: University of Illinois at Urbana–Champaign)H-Index: 1
Last. Armand Joseph Beaudoin (UIUC: University of Illinois at Urbana–Champaign)H-Index: 34
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Abstract The micro-plasticity of the Mg alloy AZ31 is explored through high-energy X-ray diffraction (HEXD). Through cyclic loading of the sample, a softening response is found to follow the resolved shear stress for basal slip. Stress relaxation is studied by applying an incremental elongation increase while continuously collecting images from a detector array. The rate exponent associated with a particular reflection is developed by evaluating the average lattice strain in the loading directio...
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