STUDY OF PROCESS PARAMETERS AND TOOL GEOMETRY FOR OPTIMISATION OF FRICTION STIR WELDING PROCESS

Abstract

The innovative process of Friction Stir Welding has generated tremendous interest since its beginning which started about two decade since its first patent in 1991 by TWI of Cambridge, England. Currently number of researchers are working to reveal the basics of this process and many aspects of it have been described. Still the process needs intensive study to evaluate production methods that will yield high quality stronger welds from the stirring action of the tool and pin into the weld plate material. In this part of the research we highlight on the study to understand the influence of tool pin geometry on friction stir welding ( FSW) of commercially pure aluminum ( IXXX according to LADS ) especially in. reference to microstructure and mechanical properties of weld in order to. optimize the welding parameters. The welding trials were made on 5mm thick plates using tools made of 310 (AISI Number) austenitic stainless steel having shoulder diameter of 25 mm and pin diameter of 6 mm. Four pin profiles namely triangular, trapezoidal, hexagonal and cylindrical are used keeping the shoulder diameter constant. Three rotational speeds and three traverse speeds are used while the tool axial tilt has been kept constant at 00. Tensile properties of the joints have been studied and their correlations with the process parameters have been analyzed. Microstructures of various zones of FSW have been studied under optical and scanning electron microscopes and they are also characterized by micro-hardness measurement.