**4. References**


MIEA is used, the solidification process tends to promote a heterogeneous nucleation, thus an auto-refinement of the grain size is promoted. However, when multi-pass welding process is employed (GMAW) columnar-epitaxial solidification prevails causing an increase in terms of grain size. On the other hand, the grain structure in the fusion zone produced by

A few mechanical properties after a welding process of 6061-T6 aluminum alloy have been presented. It is observed that quasi-static mechanical properties decrease in a dramatic manner in MIEA as well as in FSW, this aspect is totally related to the micro-structural transformation in the heat affected zone of very fine needle shape β'' precipitates to coarse bar shape β' precipitates produced by the thermal effect during the welding process (thermodynamic instability). This micro-structural transformation has been quantified by means of a micro-hardness map from which is possible to observe the soft zone formation

Fatigue crack growth behaviors in weld metal, HAZ and base metal of 6061-T6 welded joints obtained by MIEA were quantified. It was observed that the worst crack growth conditions are presented in the fusion zone (weld metal), which are related to brittle microstructure characteristics due to abundant presence of eutectic Si. A comparison between weld metal for FSW and the MIEA indicates that fatigue crack growth rate in the MIEA is higher than that in FSW; it means that for a critical crack length, the ΔK represents a 57% of the base material, whereas in the case of FSW it reaches a 79%. In addition, it was observed that the fatigue crack growth rate in the HAZ tends to be similar in both welding processes.

Ambriz, R.R., Barrera, G., & García, R. (2006). Aluminum 6061-T6 welding by means of the

Ambriz, R.R., Barrera, G., García, R., & López V.H. (2008). Microstructure and heat

indirect electric arc joint. *Soldagem and Inspecao*, Vol. 13, No. 3, pp. 255-263. Ambriz, R.R., Chicot, D., Benseddiq, N., Mesmacque, G. & de la Torre, S. (2011). Local

Ambriz, R.R., Mesmacque, G., Ruiz, A., Amrouche, A., López, V.H. (2010). Effect of the

Ambriz, R.R., Barrera, G., García, R. & López, V.H. (2010). The microstructure and

Ambriz, R.R., Mesmacque, G., Ruiz, A., Amrouche, A., López, V.H. & Benseddiq, N. (2010).

electric arc joint. *Materials and Design*, Vol. 31, No. 6, pp. 2978-2986.

*Welding and Joining*, Vol. 15, No. 6, pp. 514-521.

modified indirect electric arc process. *Soldagem and Inspecao*, Vol. 11, No. 1, pp. 10-

treatment response of 2014-T6 GMAW welds obtained with a novel modified

mechanical properties of the 6061-T6 aluminium weld using micro-traction and instrumented indentation. *European Journal of Mechanics A/Solids*, Vol. 30, pp. 307-

welding profile generated by the modified indirect electric arc technique on the fatigue behavior of 6061-T6 aluminum alloy. *Materials Science and Engineering A*,

mechanical strength of Al-6061-T6 GMA welds obtained with the modified indirect

Fatigue crack growth under a constant amplitude loading of Al-6061-T6 welds obtained by modified indirect electric arc technique. *Science and Technology of* 

FSW has the better characteristics in terms of grain size (∼10 μm).

where the failures are presented after a monotonic load (tension load).

**4. References** 

17.

315.

Vol. 527, pp. 2057-2064.


**5** 

*India* 

**Prediction of Tensile and Deep Drawing** 

R. Ganesh Narayanan1 and G. Saravana Kumar2

*2Department of Engineering Design, IIT Madras, Chennai* 

*1Department of Mechanical Engineering, IIT Guwahati, Guwahati* 

**Behaviour of Aluminium Tailor-Welded Blanks** 

Tailor-welded blanks (TWB) are blanks with sheets of similar or dissimilar thicknesses, materials, coatings welded in a single plane before forming. Applications of TWB include car door inner panel, deck lids, bumper, side frame rails etc. in automotive sector (Kusuda et al., 1997; Pallet & Lark, 2001). Aluminium TWBs are widely used in automotive industries because of their great benefits in reducing weight and manufacturing costs of automotive components leading to decreased vehicle weight, and reduction in fuel consumption. The general benefits of using TWBs in the automotive sector are: (1) weight reduction and hence savings in fuel consumption, (2) distribution of material thickness and properties resulting in part consolidation which results in cost reduction and better quality, stiffness and tolerances, (3) greater flexibility in component design, (4) re-usage of scrap materials to have new stamped products and, (5) improved corrosion resistance and product quality1. The forming behaviour of TWBs is affected by weld conditions viz., weld properties, weld orientation, weld location, thickness difference and strength difference between the sheets (Bhagwan, Kridli, & Friedman, 2003; Chan, Chan, & Lee, 2003). The weld region in a TWB causes serious concerns in formability because of material discontinuity and additional inhomogeneous property distribution. Above said TWB parameters affect the forming behaviour in a synergistic manner and hence it is difficult to design the TWB conditions that can deliver a good stamped product with similar formability as that of un-welded blank. Designers will be greatly benefited if an expert system is available that can deliver forming behaviour of TWB for varied weld and blank conditions. Artificial neural network (ANN) modelling technique is found to show better prediction of any response variable that is influenced by large number of input parameters. Artificial Neural Networks are relatively crude electronic models based on the neural structure of the brain. The building blocks of the neural networks is the neuron, which are highly interconnected. In the artificial neural networks, the neurons are arranged in layers: an input layer, an output layer, and several hidden layers. The nodes of the input layer receive information as input patterns, and then transform the information through the links to other connected nodes layer by layer to the output nodes. The transformation behavior of the network depends on the structure of the

**1. Introduction** 

1 http://www.ulsab.org

