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A method to simulate shear effects and through-thickness texture gradients in rolled sheet materials is introduced. The strain history during a rolling pass is idealized by superimposing a sine-shaped evolution of the 13 shear component to a plane-strain state. These generic strain histories are enforced in a visco-plastic self-consistent (VPSC) polycrystal deformation model to simulate texture evolution as a function of through-thickness position. The VPSC scheme is deemed superior to a full constraints (FC) or relaxed constraints (RC) approach, because it allows one to fully prescribe diagonal and shear-strain-rate components while still accounting for grain-shape effects. The idealized strain states are validated by comparison with deformation histories obtained through finite-element method (FEM) calculations. The through-thickness texture gradients are accounted for by introducing a relative variation of the sine-shaped 13 shear with respect to the plane-strain component. The simulation results are validated, in turn, by comparison with typical examples of through-thickness texture gradients observed experimentally in rolled plates and in sheets of fcc and bcc materials.

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This project is directed at advancing research and development in texture and anisotropy at Los Alamos. We are recognized as a national and international leader in texture and anisotropy research. This recognition is based on our understanding involving both quantitative texture analysis and the understanding and modeling of processes under which texture develops. In addition to these resources, we have available the full troika of texture measurement techniques, namely, x-ray, electron diffraction, and neutron diffraction. The goals of this project were (1) to increase the utilization of texture and anisotropy both within and without the Laboratory programmatic, basic, and industrial related efforts; (2) to seek to improve our texture measurement and modeling capabilities; and (3) to maintain our recognition as an international leader through basic research. These goals were accomplished through the formation of a coherent focus on texture directed through the CMS to coordinate texture efforts at the Laboratory as well as advancing the field in analysis, measurement and interpretation. The "texture focus" has essentially four functions: One, to manage the physical measurement systems; two, to coordinate human resources at the lab; three, to serve as a resource for both external and internal users; and four, to advance the field of texture analysis at all levels and keep it at the forefront.

The softening behaviour during non-isothermal annealing of a cold-rolled Al-Mn-Fe-Si model alloy was studied as a function of the state of microchemistry, in terms of the solute level of Mn, size and spatial distribution of the Mn-bearing dispersoids, as well as their temporal evolution. Microchemistry significantly affects the recrystallization microstructure, crystallographic texture as well as the mechanical property of the investigated alloy after non-isothermal annealing. The nucleation and growth of grains with different orientations are strongly dependent on both annealing temperature and microchemistry, in that pre-existing dispersoids have a less profound effect on retarding recrystallization than dispersoids forming concurrently during back-annealing. Strong concurrent precipitation suppresses nucleation and retards recrystallization, which finally leads to a coarse and pan-cake shaped grain structure, accompanied by strong P {011}<566> and/or M {113}<110> texture components and a relatively weaker ND-rotated cube {001}<310> component. A refined grain structure with medium strength P and cube {001}<100> components is obtained when the pre-existing dispersoids are coarser and fewer, and concurrent precipitation is limited. Porientated grains are less affected by second phase particles and experience a growth advantage at low annealing temperatures (<350°C), while M-orientated grains appear at higher temperatures. The intensity of the P texture does not necessarily increase with increasing supersaturation of Mn as observed during isothermal annealing, whereas the level of supersaturated Mn promotes the strength of the M texture. The mechanisms behind are discussed.

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