The Influence of Overall Texture on the Grain Boundary Network in an AZ31 Alloy

Abstract Three samples of an AZ31 alloy with distinct textures were produced through chill casting, hot extrusion and hot rolling. The as-cast material exhibited a relatively random texture, while the hot extruded and hot rolled materials displayed $$\left\{ {hki0} \right\}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfenced> <mml:mrow> <mml:mi>h</mml:mi> <mml:mi>k</mml:mi> <mml:mi>i</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:mfenced> </mml:math> prism and $$\left( {0001} \right)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfenced> <mml:mn>0001</mml:mn> </mml:mfenced> </mml:math> basal textures, respectively. This also led to significant differences in the characteristics of their grain boundary networks ( i.e. , the distribution of misorientations and plane orientations). The misorientation angle distribution of as-cast condition was similar to a random distribution. However, the other processing routes were significantly different from random, displaying a pronounced peak at ~ 30 deg misorientation angle, beyond which the distribution differed depending on the processing condition. Synthetically generated orientations belonging to each texture had misorientation angle distributions comparable to those measured for each processing route. This confirmed that the texture characteristics dictate the population of boundary misorientations. The distribution of grain boundary planes was anisotropic for all conditions, though the extent of anisotropy and their distribution characteristics depended on the processing route. It appeared that the relative areas of the grain boundary planes are largely influenced by the characteristics of the overall texture, where the hot rolling process promoted the $$\left( {0001} \right)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfenced> <mml:mn>0001</mml:mn> </mml:mfenced> </mml:math> basal plane orientation, while the $$\left\{ {hki0} \right\}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfenced> <mml:mrow> <mml:mi>h</mml:mi> <mml:mi>k</mml:mi> <mml:mi>i</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:mfenced> </mml:math> prismatic plane orientation, which does not necessarily have low energy, was dominant for the hot extrusion condition. Graphical Abstract