A polycrystal based numerical investigation on the temperature dependence of slip resistance and texture evolution in magnesium alloy AZ31B

Abstract

a b s t r a c tLow thermoplastic formability is a key factor limiting the usage of magnesium alloys, which otherwise can have broad application in automotive industry for their competitive strength to density ratio. Combining with experimental calibration and validation, we report a systematic numerical investigation about the plastic deformation of magnesium alloy AZ31B at different temperatures and subjected to different boundary conditions. By employing 3D Voronoi grains based microstructure and the crystal plasticity constitutive model developed by Staroselsky and Anand (2003), which accounts for both dislocation slip and deformation twinning in polycrystalline magnesium, we estimate the dependence of critical resolved shear stresses (CRSS) of different slip/twinning systems on temperature. We further obtain the fractional plastic strains contributed by individual slip/twinning systems at different loading conditions. Grain level deformation analysis indicates that there exists significant stress and plasticity inhomogeneity among grains.

A new thermo-elasto-plasticity constitutive theory for polycrystalline metals

“…However, due to the low symmetry of the crystallographic structure of the HCP polycrystalline metals, one must carefully take into account the details of the stress/strain variations from the grain, and the interaction between the crystals and grains. Also, different types of slip systems exist, and both slip and twinning contribute to the plastic deformation in the HCP crystals [17,49,50]. As the temperature increases, the plastic deformation transits from being twinning dominated to a combination of slip and twinning [49] or slip dominated [43].…”

“…Also, different types of slip systems exist, and both slip and twinning contribute to the plastic deformation in the HCP crystals [17,49,50]. As the temperature increases, the plastic deformation transits from being twinning dominated to a combination of slip and twinning [49] or slip dominated [43]. All the above factors show that the simulation of the plastic behaviors at different temperatures for the HCP is more difficult than for the FCC.…”

A microstructure based analytical model for tensile twinning in a rod textured Mg alloy

“…The effect of twinning has been incorporated into various crystal plasticity codes (Beyerlein et al, 2011;Beyerlein and Tome, 2010;Capolungo et al, 2009;Clausen et al, 2008;Fernández et al, 2013;Gu et al, 2013;Li et al, 2013;Liu and Wei, 2013;Niezgoda et al, 2013b;Oppedal et al, 2011;Oppedal et al, 2013;Proust et al, 2009;Wang et al, 2010a;Wang et al, 2013a;Wang et al, 2013b). These capture the strong asymmetric anisotropy but typically do so without explicitly considering twin nucleation and growth, which operate under different stresses (Christian and Mahajan, 1995).…”

An examination of strain ageing in a Mg–Y–Zn alloy containing Gd

“…Both alloy families show very high strength with reasonable ductility, with composite-like alloys composed of a Mg matrix with large volume fraction of second phase receiving most attention [11,12]. Factors such as precipitation kinetics and second phase evolution during heat treatments [6][7][8][9][10][13][14][15][16], and changes of microstructure and texture during thermomechanical processing [17][18][19][20][21] are receiving most attention. Other studies are examining deformation mechanisms within the matrix and second phases [12,[21][22][23][24] to understand how strengthening is achieved.…”