Sheet metal formability is generally affected by crystallographic texture. In particular, bendability and deep-drawability of aluminum and its alloys are closely related to the recrystallization texture of the rolled sheets. It is necessary to quantitatively predict them from a viewpoint of texture control. This paper described a method for simultaneous prediction of both the bendability and the deep-drawability on the basis of the average Taylor factor as a polycrystal calculated by using an orientation distribution function. The normalized Taylor factor (M_n-value) and the r-value were used as measures of bendability and deep-drawability, respectively. The predicted results from ideal orientations demonstrated that ｛001｝〈100〉 orientation had excellent bendability and bad deep-drawability, whereas ｛111｝〈110〉 orientation had bad bendability and excellent deep-drawability. The predicted results for some aluminum alloys suggested that conventional cold-rolled and annealed sheets would be favorable to bendability, and the addition of asymmetric warm rolling after cold rolling would lead to improved deep-drawability.

In this study, plane strain compression has been applied to aluminum alloy with dispersed Pb particles for local strain measurement. The 3D local plastic strains of individual grains were investigated using synchrotron radiation tomography (CT) by tracking the marker Pb particles. Crystallographic orientations in the inside of grains were also measured on the polished cross-section of the strain-measured sample by means of EBSD. The relationship between local plastic strain and local misorientation within grain was investigated on individual grain with considering orientation components of typical rolling texture. It is suggested that the experiment can discover mechanisms of microstructural evolution induced by plastic deformation in polycrystalline metals, although clear relationship between them could not be definitely clarified in this research due to only one condition of the plane strain compression.

The effect of roll diameter and pass schedule on the cold rolling and recrystallization texture of 1050 aluminum was investigated using the X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) methods. Shear textures 〈110〉//RD, {111}//ND, and, especially, RW{001}〈110〉 developed on the plate surface of A1050 with an increase in roll diameter and a reduction per pass in the cold rolling process. When rolling with various roll diameters, the development of shear textures can be described using the roll gap ratio, which is defined as the ratio of the contact length and average thickness. Shear textures on the plate surface developed with a high roll gap ratio when the roll diameter was large and the reduction per pass was high. However, the development of the rolling textures of the copper, S, and brass components was inhibited. Moreover, in the central layer of the thickness, the rolling texture developed independent of the roll diameter and the reduction per pass. In the case of the shear textures that were developed on the plate surface after cold rolling, the RW{001}〈110〉 texture remained after annealing even though the {111}//ND texture disappeared. Moreover, the cube texture was enhanced with the development of the rolling texture because of cold rolling. These results suggest that shear textures in both the cold-rolled and annealed plates can be developed cold rolling with a large roll diameter and high reduction per pass.

The effects of precipitation and cold-rolling reduction on recrystallization textures of an Al–Mg–Si alloy were investigated. The sample sheets were prepared by solution heat treatment followed by intermediate annealing (IA) at 623 K for 1 h (IA-1 h) or 110 h (IA-110 h). Other sheets were prepared without IA (non-IA). These samples were rolled at ambient temperature up to 97.5% reduction followed by a final annealing step at 623 K. The recrystallization textures changed depending on the IA conditions. In the IA-1 h sample, the cube texture ({001}〈100〉) increased with increasing reduction. In contrast, in the non-IA sample and IA-110 h sample, the cube texture decreased at high rolling reduction. Shear bands were formed in the cold-rolled non-IA sample. Shear bands could be the nucleation sites of randomly oriented grains in the recrystallization process. Meanwhile, in the IA-110 h sample, the particle stimulated nucleations (PSN) of recrystallized grains by coarse precipitates were observed. Grains generated by PSN are expected to be randomly oriented. Therefore, the nucleation at shear bands and PSN cause a decrease in the cube texture. In addition, decreasing of the cube texture at high reduction is assumed to be caused by increasing of shear bands and deformation zones around coarse precipitates.

The effects of thermally stabilized particles in Al–Mg–Si alloy on recrystallization behavior were investigated to obtain fundamental knowledge to control microstructure, texture and mechanical properties of this alloy. In this study, the Al–Mg–Si–Sc–Zr alloy was cast, homogenized and hot rolled. Three types of spherical Al₃(Sc, Zr) particles with L1₂ structure: rod-like incoherent, spherical semi-coherent and spherical incoherent particles were observed in the hot-rolled sample in the Al–Mg–Si–Sc–Zr alloy by using TEM, STEM and EDS. In addition, it was found that all particles have the core-shell structure with the core enriched with Sc and the shell enriched with Zr atoms by 3D-ET and STEM-EDS. It is considered that these particles are formed during casting, homogenized treatment and hot rolling. The results of crystal orientation distribution of annealed sample after cold rolling indicated that the presence of Al₃(Sc, Zr) particles may interfere with the recrystallization (the grain growth) until 600°C. From the comparison with the driving force of primary recrystallization and grain growth, and the pinning force of Al₃(Sc, Zr) particles, it was suggested that these particles mainly contribute to the suppression of grain growth. The results of in-situ heating SEM/EBSD analysis of cold rolled Al–Mg–Si–Sc–Zr alloy supported the suggestion.

In order to improve deep drawability of Al–Mg–Si alloy sheets for automobile body panels, texture control for increasing the r-value of the sheets was performed for a 6022 aluminum alloy processed by cold rolling and differential-speed warm rolling. Recrystallization texture including {111}〈110〉 orientation favorable to deep drawability developed after the three-step annealing proposed in this paper, which consists of the two-step annealing for recrystallization and the final solution treatment. The heating process in the first stage of the annealing affects the evolution of {111}〈110〉 recrystallization texture most strongly. In the heating process, the {111}〈110〉 orientation developed with increasing temperature, while the intensity of {001}〈100〉 (cube) orientation unfavorable to deep drawability decreased after it increased. As a result, recrystallization texture of a sample obtained through the three-step annealing process had considerably weaker {001}〈uv0〉 components than that of an only solution-treated sample in addition to a main {111}〈110〉 component.

Texture evolution in commercial purity aluminum sheet subjected to asymmetric rolling (ASR) with one pass of high reduction has been investigated. Warm ASR with high differential speed ratios of 2 and 2.5 was applied in order to impose strain for the annealed sheet after cold rolling. The sheet was asymmetrically rolled in the direction parallel to the original rolling direction (RD) or 45° from the rolling direction (RD+45°). The one pass ASR at a temperature ranging from 423 to 473 K imposed shear strain on the sheet. Finer grain structure in the faster roll side was formed by the warm ASR and subsequent annealing. The shear texture component E{111}〈110〉 mainly evolved in the specimen subjected to ASR and annealing. The higher fraction of E component was obtained in the ASR direction of RD+45°, which was related to the initial texture before the ASR.

The authors measured texture change during uniaxial tensile deformation of extruded bar of AZ31 magnesium alloy by time-of-flight neutron diffraction and EBSD (electron backscatter diffraction). Texture measurement by neutron diffraction revealed the transition of tensile axis distribution in overall gauge volume during the deformation. The concentration of the tensile axis initially observed at 〈213̄0〉. With increasing strain, the dominant peak appeared at 〈9 1 ̄10 0〉 and the initial peak weakened. It was also found that the total density of 〈hki0〉 decreased during the deformation. EBSD showed activations of {101̄1} compression twinning and following double twinning. The twinned region were oriented away from the 〈hki0〉 orientation group. The amount of twinning gradually increased with increasing strain. On the other hand, the deformation of the matrix was achieved by slip deformation, resulting in the formation of the peak at 〈9 1 ̄10 0〉. Based on the above results, it was concluded that the reason for poor ductility of magnesium alloys may not be a lack of 〈c+a〉 slip but twinning and deformation concentration inside of the twins.