An Experimental Analysis on Mechanical Integrity of Tig-Mig Hybrid Weldments
Tungsten Inert Gas (TIG) welding and Metal Inert Gas (MIG) welding are now commonly employed independently in welding applications, owing to their distinct advantages such as high deposition rate, production efficiency, especially the ability to accomplish high speed welding of thick plates or solid rods. Moreover clean and sound joints, narrow heat affect zone, better weld shape and deeper weld penetration are additional features of these two arc welding processes. As a result, mechanical properties of welded assemblies are much enhanced particularly, joints made of stainless steel, magnesium alloys and low carbon steels. In this project, the main objective is to develop a new hybrid TIG/MIG welding method for joining dissimilar metal weldments, examine the mechanical integrity of the welded joints and compare the results with that of individual welding methods (TIG and MIG independently). In literature, TIG and MIG weldments are performed independently and the results are compared in welding stainless steel and mild steel materials. In this attempt, this work is extended by developing a hybrid welding method combining TIG and MIG welding methods to weld dissimilar metallic materials. Conventionally, mechanical integrity of weldments is analysed through investigating the mechanical properties such as yield strength, ultimate tensile strength, % reduction area and % elongation values related to the weldments. In this attempt too, all of the above integrity elements are measured and analysed for a comprehensive comparative outcomes. AWS standards are used to prepare the welding specimens and CNC lathe machine was used to produce the welding specimens that are made of SS 304 grade steel and Mild Steel materials. Design of the experiments and methodology are suitably planned after deciding the number of sample weldments and the key parameters of welding are analysed and compared with TIG and MIG with TIG/MIG hybrid. The experimental results reveal that the TIG/MIG hybrid method proves to be a prospective alternative for TIG and MIG methods and in most of occasions and parameter set, it is found to result in better mechanical properties.