Texture analysis of the effect of non-basal slip systems on the dynamic recrystallization of the Mg alloy AZ31

2013 ◽  
Vol 75 ◽  
pp. 101-107 ◽  
Author(s):  
B. Srinivasarao ◽  
N.V. Dudamell ◽  
M.T. Pérez-Prado
Author(s):  
Maria-Gema Llorens ◽  
Albert Griera ◽  
Florian Steinbach ◽  
Paul D. Bons ◽  
Enrique Gomez-Rivas ◽  
...  

The flow of glaciers and polar ice sheets is controlled by the highly anisotropic rheology of ice crystals that have hexagonal symmetry (ice lh). To improve our knowledge of ice sheet dynamics, it is necessary to understand how dynamic recrystallization (DRX) controls ice microstructures and rheology at different boundary conditions that range from pure shear flattening at the top to simple shear near the base of the sheets. We present a series of two-dimensional numerical simulations that couple ice deformation with DRX of various intensities, paying special attention to the effect of boundary conditions. The simulations show how similar orientations of c -axis maxima with respect to the finite deformation direction develop regardless of the amount of DRX and applied boundary conditions. In pure shear this direction is parallel to the maximum compressional stress, while it rotates towards the shear direction in simple shear. This leads to strain hardening and increased activity of non-basal slip systems in pure shear and to strain softening in simple shear. Therefore, it is expected that ice is effectively weaker in the lower parts of the ice sheets than in the upper parts. Strain-rate localization occurs in all simulations, especially in simple shear cases. Recrystallization suppresses localization, which necessitates the activation of hard, non-basal slip systems. This article is part of the themed issue ‘Microdynamics of ice’.


2005 ◽  
Vol 486-487 ◽  
pp. 249-252 ◽  
Author(s):  
Chang Yong Lee ◽  
Won Bae Lee ◽  
Yun Mo Yeon ◽  
Seung Boo Jung

Friction stir welding of dissimilar formed Mg alloys(AZ31/AZ91) was successfully carried out at the limited welding conditions. In a sound joint, SZ was mainly consisted of AZ31 Mg alloy which was located the retreating side. Dynamic recrystallization and grain growth occurred and β intermetallic compounds of AZ 91 Mg alloy was not observed in SZ. BM had a higher hardness than that of the weld zone. The fracture location was not weld zone but BM of the AZ91 Mg alloy in tensile test.


1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.


2020 ◽  
Vol 822 ◽  
pp. 153282 ◽  
Author(s):  
David Canelo-Yubero ◽  
Zsolt Kovács ◽  
J.F. Thierry Simonet Fotso ◽  
Domonkos Tolnai ◽  
Norbert Schell ◽  
...  

2015 ◽  
Vol 752-753 ◽  
pp. 448-451
Author(s):  
Mária Kapustová ◽  
Mariana Balážová

This contribution analyses influence of thermo mechanical conditions of magnesium alloy - type AZ31 forming on its flow stress. Temperature and strain/deformation rate belong to the essential thermo mechanical parameters of strain/deformation process. A testing cylinder made of selected Mg alloy was strained using pressure at warm temperatures within defined two degrees of nominal strain 30% and 60% and strain rate of 5 s-1. The pressure test at warm temperatures was conducted at testing temperatures 250, 300 and 350°C. It is important to explore the temperature influence on AZ31 alloy flow stress in order to reduce energy consumption of formed pieces production. Surface quality and precision of required dimension will improve, as well. The experiment was aimed at graphic evaluation of temperature influence on flow stress of Mg alloy AZ31B. Resulting form flow stress curve it is possible to read out its value for particular strain. These values are essential for calculation of forming force and work. For magnesium alloy AZ31 warm forming at temperature interval of 230 - 425°C is typical. The pressure tests were realized within the temperature interval of 250 - 350°C, i. e. at temperatures belonging to lower limit of recommended temperature interval, with the aim of acquirement as much information as possible on Mg alloy behavior at low forming temperatures.


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