An Investigation of Detwinning Behavior of In-plane Compressed E-form Mg Alloy During the In Situ Tensile Test
01 Jan 2019-pp 201-206
TL;DR: In this article, the detwinning phenomenon of in-plane compressed E-form magnesium alloy sheet was investigated using in situ tensile test combined with electron backscattered diffraction (EBSD) technique.
Abstract: In this study, we investigated the detwinning phenomenon of in-plane compressed E-form magnesium (Mg) alloy sheet systematically using in situ tensile test combined with electron backscattered diffraction (EBSD) technique. Microstructure and microtexture evolutions were analyzed at different tensile strains during the in situ tensile test. The detwinning phenomenon in E-form Mg alloy was found to be linked to both twin boundary mobility and the interaction of their boundaries with dislocations. The pre-compressed sheet of E-form Mg alloy effectively accommodated the thickness direction strains generated during the in situ tensile test. The effect of detwinning on formability and mechanical behavior of the E-form Mg alloy was also examined. EBSD results indicate that most of the deformation twins formed during in-plane compression were removed when the load is reversed during the in situ tensile test.
References
More filters
TL;DR: In this paper, some studies have confirmed that pre-twinning can be an effective way to enhance the strength, formability and mechanical anisotropy of magnesium alloys.
164 citations
TL;DR: In this article, the Mg-6Al-1Zn magnesium alloy sheets were rolled at high temperatures of 723-793 K using differential speed rolling and the Erichsen value remarkably increases about 1.5 times due to the weakened basal texture regardless of the coarser grains with increasing the rolling temperature from 723 to 793 K.
151 citations
25 Oct 2008-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the formation mechanisms of corresponding morphologies are proposed based on twinning and detwinning processes during compressive and tensile loading half cycles, respectively, for this alloy.
Abstract: Typical fracture morphology of Mg–3%Al–1%Zn (AZ31) alloy after low cycle fatigue was investigated using SEM and optical microscope. It is shown that prolific lamellar structure in the crack initiation and crack stable propagation zone mainly results from twinning, while dimple structure formed in the unstable crack propagation and final rupture zone is mainly due to slip. The formation mechanisms of corresponding morphologies are proposed based on twinning and detwinning processes during compressive and tensile loading half cycles, respectively, for this alloy.
150 citations
20 Aug 2013-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the activation of detwinning and basal slip in twinned region was found to effectively accommodate a thickness-direction strain and this led to an enhancement of stretch formability.
Abstract: A remarkable improvement of the stretch formability of rolled Mg–3Al–1Zn alloy at room temperature was achieved by introducing initial {10–12} twins. The activation of detwinning and basal slip in twinned region was found to effectively accommodate a thickness-direction strain and this led to an enhancement of stretch formability. The improvement was obtained in proportion to the twin volume fraction and just the twin volume fraction of ∼24% enhanced the stretch formability by ∼65%, which can be achievable at 300 °C.
97 citations
20 Oct 2013-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the authors investigated the nonlinear response arising during unloading under in-plane uniaxial compression of a rolled magnesium alloy sheet using a crystal plasticity finite-element method, focusing on the effects of twinning and detwinning, and discuss the mechanism that causes the non-linear response to be more pronounced under uniaoXial compression than under uniaXial tension.
Abstract: We investigate the nonlinear response arising during unloading under in-plane uniaxial compression of a rolled magnesium alloy sheet using a crystal plasticity finite-element method, focusing on the effects of twinning and detwinning, and discuss the mechanism that causes the nonlinear response to be more pronounced under uniaxial compression than under uniaxial tension. In the simulation, we employed a twinning and detwinning model recently proposed by the authors. From numerical experiments, we confirmed that, as already noted in previous studies, detwinning activity plays an important role in the nonlinear response during unloading. However, we also found that the basal slip could become very active during unloading because of the dispersion of crystallographic orientations caused by twinning activity during loading, which is another factor in the pronounced nonlinear response during unloading under uniaxial compression. We conclude that the nonlinear response during unloading is more pronounced under uniaxial compression than under uniaxial tension because of these two factors—i.e., the detwinning activity and the pronounced basal slip activity—which are not present under uniaxial tension.
77 citations