Polycrystalline behavior analysis of extruded magnesium alloy AZ31
Tóm tắt
Uniaxial tensile and compressive tests were performed at room temperature on extruded AZ31 Mg alloy specimens and distinct tensile-compressive anisotropy was detected. Deformed specimens were examined and the results indicate that the generation of {10
$\bar 1$
2}〈10
$\bar 1$
1〉 twin is responsible for the mechanical anisotropy. A rate independent crystal plasticity model, which accounts for both slip and twinning, was developed for polycrystalline hexagonal close packed (HCP) materials. Model predictions for the stress-strain curves and texture evolution were in reasonable agreement with the experimental results. Specifically, the model captured the three stages of strain hardening for uniaxial-compression. By comparing stress-strain curves and texture evolution between model predictions and experimental measures, information about the dominant slip and twinning systems active at room temperature was deduced.
Tài liệu tham khảo
Yoo M H. Slip, twinning, and fracture in hexagonal close-packed metals [J]. Metallurgical and Materials Transactions A, 1981, 12A(3): 409–418.
Wang Y N, Huang J C. The role of twinning and untwinning in yielding behavior in hot-extruded Mg-Al-Zn alloy [J]. Acta Materialia, 2007, 55(3): 897–905.
Brown D W, Agnew S R, Bourke M A M, et al. Internal strain and texture evolution during deformation twinning in magnesium [J]. Materials Science and Engineering A, 2005, 399(1–2): 1–12.
Barnett M R, Keshavarz Z, Beer A G, et al. Influence of grain size on the compressive deformation of wrought Mg-3Al-1Zn [J]. Acta Materialia, 2004, 52(17): 5093–5103.
Nave M D, Barnett M R. Microstructures and textures of pure magnesium deformed in plane-strain compression [J]. Scripta Materialia, 2004, 51(9): 881–885.
Kleiner S, Uggowitzer P J. Mechanical anisotropy of extruded Mg-6%Al-1%Zn alloy [J]. Materials Science and Engineering A, 2004, 379(1–2): 258–263.
Chino Y, Kimura K, Hakamada M, et al. Mechanical anisotropy due to twinning in an extruded AZ31 Mg alloy [J]. Materials Science and Engineering A, 2008, 485(1–2): 311–317.
Jiang L, Jonas J J, Luo A A, et al. Influence of {10–12} extension twinning on the flow behavior of AZ31 Mg alloy [J]. Materials Science and Engineering A, 2007, 445–446(15): 302–309.
Tang W Q, Zhang S R, Peng Y H, et al. Simulation of magnesium alloy AZ31 sheet during cylindrical cup drawing with rate independent crystal plasticity finite element method [J]. Computational Materials Science, 2009, 46(2): 393–399.
Wang X M, Xu B X, Yue Z F. Micromechanical modelling of the effect of plastic deformation on the mechanical behaviour in pseudoelastic shape memory alloys [J]. International Journal of Plasticity, 2008, 24(8): 1307–1332.
Takahashi H. Stress-strain relations of polycrystalline metals. 3. Proportional loading of FCC metals [J]. Bulletin of the Japan Society of Mechanical Engineers, 1976, 19(136): 1115–1121.
Tomé C N, Lebensohn R A, Kocks U F. A model for texture development dominated by deformation twinning: Application to zirconium alloys [J]. Acta Metallurgica et Materialia, 1991, 39(11): 2667–2680.
Koike J. Enhanced deformation mechanisms by anisotropic plasticity in polycrystalline Mg alloys at room temperature [J]. Metallurgical and Materials Transactions A, 2005, 36A(7): 1689–1696.
Christian J W, Mahajan S. Deformation twinning [J]. Progress in Materials Science, 1995, 39(1–2): 1–157.
Styczynski A, Hartig Ch, Bohlen J, et al. Cold rolling textures in AZ31 wrought magnesium alloy [J]. Scripta Materialia, 2004, 50(7): 943–947.