Experimental Investigations And Parametric Optimization Of Joining In718 Alloy By Variants Of Tig Welding

Abstract

ABSTRACT newline newline newline newline newlineIn the present world scenario, welding is widely employed in aerospace, automotive industries, nuclear industries and shipbuilding, etc. Among the various welding processes, Tungsten Inert Gas (TIG) welding plays a major role in the welding of Nickel Alloys, Aluminum Alloys, Titanium and Stainless Steel which are difficult to weld by other welding processes. It gives superior quality welds compared to other mostly used arc welding processes like Manual Metal Arc Welding (MMAW) and Gas Metal Arc Welding (GMAW). Therefore TIG welding can be used to provide a potential solution for joining thin-gage ferrous and non-ferrous metal in automotive, aerospace and nuclear industries. newlineDifferent types of Nickel base alloys are available, which may differ from each other based upon their alloying elements. In this work, the Nickel base precipitation strengthened super alloy Inconel 718 (IN718) is selected as a base material, because it is widely used for applications in aerospace, power and nuclear industries due its wide range of applications which is included the temperature range from subzero temperature to 650and#9702;C. newlineThe weldability of IN718 alloy using TIG welding process is facing various weld defects due to the selection of improper welding process parameters. Hence, it is very necessary to overcome these problems for attaining better weld quality joints. The quality of the TIG welding is improved through the development of different variants of TIG welding process. In this research three mostly used and economical variants of TIG welding process are experimented. They are namely Constant Current TIG (CTIG), Pulsed Current TIG (PTIG) and Hybrid Pulsed TIG (HPTIG). In this research these variants of TIG welding processes are experimented for obtain optimum room temperature mechanical properties (Ultimate Tensile Strength (UTS), Yield Strength (YS), Elongation (E) and Microhardness (MH)), subzero (-196and#9702;C) temperature tensile properties (UTS, YS, and E) and bead profile dimensions (Bead Depth,