Microstructure and texture evolution of AZ31 Mg alloy after uniaxial compression and annealing

The effect of initial texture on the microstructure and texture evolution of as extruded AZ31 alloy after hot uniaxial compression at 430°C and subsequent annealing at 450°C for 72h has been investigated using electron backscatter diffraction.Samples were machined from the extruded block in such orientations that the compression axis,CD,was parallel(CD0ED)or perpendicular(CD90ED)to the initial extrusion direction,ED,respectively.Results show that the deformation microstructure for both samples was characterized by equiaxed grains that resulted from dynamic recrystallization.Annealing at 450°C for 72 h led to the increase of grains size to 28 and 25μm for CD0ED and CD90ED samples,respectively.A random deformation texture was developed in CD0ED sample while the deformation of CD90ED developed typical(0002)basal texture.The deformation textures of both samples were retained after subsequent annealing at 450°C for 72 h.The flow behavior was affected by the initial texture.The CD0ED sample showed the highest work hardening.These evolutions were explained in term of the activation and suppression of basal,non-basal slip and mechanical twinning.©2018 Published by Elsevier B.V.on behalf of Chongqing University.This is an open access article under the CC BY-NC-ND license.

Microstructural and textural investigation of an Mg-Dy alloy after hot plane strain compression

The microstructure and texture development in a Mg-0.41Dy(wt%)alloy after plane strain compression(PSC)at 300℃under a strain rate of 10^(-2)and 10^(-4)s^(-1),up a final true strain of—1.2 were investigated using electron backscatter diffraction(EBSD)and X-ray diffraction.At high strain rate of 10^(-2)s^(-1),the microstructure exhibited massive twins mainly{101^(-)2}extension,{1011}contraction and{101^(-)3}-{101^(-)2}double twin due to the random texture of the as-cast alloy.Meanwhile,at a low strain rate of 10^(-4)s^(-1),the microstructure was characterized by dynamic recrystallization at the{101^(-)2}extension,(101^(-)1)contraction twins and grain boundaries.Twin dynamic recrystallization(TDRX),rotational dynamic recrystallization(RDRX)and discontinuous dynamic recrystallization(DDRX)were the main mechanisms responsible for the formation of recrystallized grains.The texture was characterized by the formation of three fibers:basal<0001>,<101^(-)0>//CD and<112^(-)0>//CD where CD is the compression direction.Moreover,the texture was less sensitive to the deformation conditions since the recrystallized grains showed the same orientation than twins.The changes of the mechanical properties of the alloy were ascribed to the resulting microstructure due to the twinning and dynamic recrystallization.