15. Conclusions

component represented 300°C (blue colour) at ф<sup>1</sup> = 35°, ф = 45° and ф<sup>2</sup> = 0° shows

Efforts have been made in recent years to incorporate the plastic anisotropy resulting mainly from a crystallographic texture to the modelling of the deformation of polycrystalline solids [19]. Two types of procedures have been currently being used. The first involved direct crystal plasticity [20], whereas the second represented the yield surface by a closed-form, analytical expression [10, 21]. FLD predictions were compared with the experimental data of annealed aluminium (AA6xxx) sheet. It was found that the Goss orientation {0 1 1}<100> present in the initial texture and the microstructure influenced the formability significantly.

Wu et al. [12] investigated the effect of the cube texture on the initiation of localized necking, while the ideal cube texture showed decreased formability; for a sheet undergoing biaxial tension, a spread about the cube significantly delayed the initiation of localized necking. The effect of a widespread cube texture on the FLD was path dependent; it decreased the formability for strain paths far away from the equi-biaxial stretching but increased the formability significantly near the equibiaxial stretching mode. Theoretically, the change in formability near equi-biaxial stretching could be correlated to the sharpness of the yield locus at equi-biaxial

As the annealing temperature increased, the recrystallization and precipitation rates increased [22, 23], which, in turn, resulted in a decrease in time to obtain the conductivity saturating level, and the solute solubility increased resulting in a decrease in the peak conductivity. Creating better texture helped to develop sheet metals with higher formability. By correlation of the parameters, the texture can be

Galand et al. [24] have focused on the influence of interconnected Cu microstructure on the electro-migration phenomenon. The microstructure and texture of copper were characterized by electron backscatter diffraction (EBSD). In both cases, no significant differences were observed in terms of the reliability performance versus annealing conditions. On the contrary, a large difference was

observed on the electron backscatter diffraction results. Then, a statistical approach was used to investigate local microstructure and texture of copper for 150 nm line width. The results indicated that the morphological parameters of copper can vary with annealing conditions but could lead to similar reliability performances. It was concluded that these parameters had no relationship with electromigration phenomena in the interconnects. On the other hand, a high amount of

disorientation has been highlighted as responsible for early failures. Also

optimized. Literatures related to texture optimization have been given.

14. Microstructure and texture versus annealing

Hence these experimental results could not be directly interpreted, but it can be interpreted by fitting these results into the models by simulation approach, which has been discussed in the later part of the section using response surface methodology.

inconsistent intensity.

Aluminium Alloys and Composites

tension.

52

12. FLD using crystal plasticity models

13. Effect of cube texture on sheet metal formability

This chapter clearly explains the interlinking nature of aluminium and its alloys in terms of its physical size like sheet thickness, annealing temperature, sheet (rolling) orientation, chemical composition versus tensile properties, formability properties, texture properties and void coalescence properties. The desired formability can be seen through the better crystallographic evolution and microstructure or from the fractography void coalescence results. Furthermore investigations could be carried out to prove a well-established strong outcomes in this area.
