Essay On Friction Stir Welding

1. Introduction

Friction stir welding is a solid state welding process; this remarkable up-gradation of friction welding was invented in 1991 in The Welding Institute [1]. Figure 1 shows the schematic representation of the Friction Stir Welding process. The process starts with clamping the plates to be welded to a backing plate, so that the plates do not fly away during the welding process. A rotating wear resistant tool is plunged on the interface between the plates to a predetermined depth and moved forward in the interface between the plates to form the weld. The external tool has a probe and shoulder which stirs the material to be joined and forges the surface. FSW comes together with forging and extrusion processes. The probe and shoulder extrudes the material by stirring and the shoulder alone forges the material surface to be joined.

Friction Stir Welding facilitates welding of plate to plate joints for several applications. This process is chosen for the welding of AA 6082-T6 (Al-Mg-Si alloy) of various thicknesses. This alloy finds use in structural and other industrial applications. FSW process is especially well suited to butt and lap joints in aluminium. Production of aluminium alloy components is not very complex but joining of these materials can sometimes

But the grain size ranges between 3 μm to 6 μm, 3 μm to 8 μm and 4 μm to 9 μm for 4 mm, 6 mm and 8 mm plates respectively. Higher polygon pin face edges approach circular pin, this vanishes the pulse formation in stirring. This leads to distorted grains due to decrease in dynamic area or lack of sweeping between tool and material. Whereas a low number of polygon pin face edges generates higher dynamic area. This shows the coarse grains relatively. The grain size ranges between 5 μm to 7 μm, 6 μm to 8 μm and 7 μm to 9 μm for 4 mm, 6 mm and 8 mm plates