International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 02 | May-2015 www.irjet.net p-ISSN: 2395-0072 © 2015, IRJET.NET- All Rights Reserved Page 1086 Mechanical Characterization of Aluminium Alloys for TIG Welding- Experimental and Modeling Studies Sunil M. Pawar 1 , Prof. Vivek V. Kulkarni 2 1 Student, Department of mechanical Engineering, KLS Gogte Institute of Technology, Karnataka, India 2 Asst. professor, Department of mechanical Engineering, KLS Gogte Institute of Technology, Karnataka, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - In the past, researchers did not consider welded joints in their finite element models. This could give large discrepancies to the mechanical characteristics of the structure and consequently would lead to inaccuracies in their predicted results. This paper attempts to present an appropriate way to model welded joints in a structure using the finite element method. Initially, two single-plates were developed in 3-dimensional finite element model and then welded. Later all three parts are assembled in CREO software. The two plates were joined together to form a single butt-joint of simple structure that involved gas tungsten arc welded (GTAW) joint. Mechanical characteristics of the butt-joint structure were determined experimentally and by finite element analysis and the predicted results were then compared with each other. FEA analysis is carried out in ANSYS 14.0 V software. Key Words: Aluminium alloy, Specimen, Tungsten Inert Gas (TIG) welding, GTAW joint, Filler rod 1. INTRODUCTION Aluminium alloys are widely used to produce aerospace components with high specific strength. High strength precipitation hardening 7xxx series aluminium alloys, such as 7075 are used extensively in aerospace industry [1]. 7xxx series alloys are heat treatable with ultimate tensile strength of 520 MPa. The commonly welded alloys in this series such as 7075 are predominantly welded with the 5xxx series filler alloys. Today's aluminium alloys together with their various tempers, comprise a wide welding procedure development. It is important to understand the differences between the many alloys available and their various performances and weld ability characteristics. When developing arc weld procedures for these alloys, consideration must be given to the specific alloy being welded [1]. It is often said that arc welding of aluminium is not difficult; it is just different it is believed that an important part of understanding in differences is to become familiar with the various alloys 2. ANALYTICAL WORK In the present work, tensile test analysis of a V-butt jointed specimen is conducted in a virtual environment. The material used for the analysis is AA7075-T6 aluminium alloy, whose composition is listed in Table 1. Table -1: Chemical composition of AA7075-T6 Material type Composition in % Silicon 0.067 Iron 0.0236 Copper 1.640 Manganese 0.041 Magnesium 2.670 Nickel 0.004 Zinc 6.070 Titanium 0.054 Lead 0.002 Tin 0.001 Aluminium 89.00 1.1 TIG welding In TIG welding processes, the arc is struck from a consumable electrode to the work piece and metal has been melted from electrode, transferred across the arc and finally incorporated into the molten pool. TIG process employs an electrode, made from high melting point metal, usually a type of tungsten, which is not melted. The electrode and the molten pool are shielded from the atmosphere by a stream of inert gas which flows around the electrode and is directed onto the workpiece by a nozzle which surrounds the electrode. In TIG welding, the primary functions of the arc are to supply heat to melt the workpiece and any filler metal which may be necessary.