11.5 α-Fibre and β-fibre

From the α-fibre, it can be inferred that the Goss components increased with simultaneous fall in the orientation densities (f(g)) of deformation components as can be seen from the β-fibre (Figure 17) for Al 8011 alloy. The cube orientation showed a strong scattering along the RD in the φ2—0° section.

Figure 18 showed that the formability in the present set of samples improved with increasing annealing temperature. The presence of precipitates could significantly suppress the cube fraction in the microstructure in turn retaining the deformation components at lower temperatures.

The alpha-fibre plots followed a similar trend in all the cases, particularly at starting (ф = 0°) and end (ф = 90°) locations. As there is an increased annealing temperature, the intensity of alpha-fibre also increases. The trend was different at ф<sup>1</sup> = 35°, where a peak change is observed at all alpha-fibre components. In general, a deep change (intensity of alpha-fibre component) was observed at other annealing temperatures except 300°C. This was due to the equilibrium between precipitation and recrystallization at that temperature. Hence alpha-fibre

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

disorientation resulting in high mean disorientation and high grain boundary

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

The authors would like to thank our masters, Dr. R. Narayanasamy and Dr. Satyam Suwas, for their input and our beloved daughter V. Suryameena for her

be carried out to prove a well-established strong outcomes in this area.

This chapter clearly explains the interlinking nature of aluminium and its alloys

densities were the root cause of early failures.

Aluminium and Its Interlinking Properties DOI: http://dx.doi.org/10.5772/intechopen.86553

15. Conclusions

Acknowledgements

support.

Author details

K. Velmanirajan<sup>1</sup>

Tamil Nadu, India

53

Virudhunagar, Tamil Nadu, India

provided the original work is properly cited.

\* and K. Anuradha<sup>2</sup>

\*Address all correspondence to: velmanirajan@gmail.com

1 Department of Mechanical Engineering, VSVN Polytechnic College,

2 Department of Chemistry, Sri Meenatchi Government Arts College, Madurai,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

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.

#### 12. FLD using crystal plasticity models

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.

### 13. Effect of cube texture on sheet metal formability

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 tension.

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 optimized. Literatures related to texture optimization have been given.

#### 14. Microstructure and texture versus annealing

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

disorientation resulting in high mean disorientation and high grain boundary densities were the root cause of early failures.
