EXPERIMENTAL ANALYSIS OF FSW FOR DISSIMILAR ALUMINIUM ALLOYS AA6061 AND AA4043 USING CNC VMC

Abstract

Friction Stir Welding process (FSW) is a solid state welding process in which the relative motion between the tool and
the work piece produces heat which makes the material of two edges being joined by plastic atomic diffusion. This
method relies on the direct conversion of mechanical energy to thermal energy to form the weld without the
application of heat from conventional sources. The rotational speed of the tools, the axial pressure, welding speed and
the tool profile are the principal variables that need to be controlled in order to provide combined heat and pressure to
form the weld. The scope of this investigation is to evaluate the effect of joining parameter on the mechanical
properties of dissimilar aluminium alloys AA6061 and AA4043 joints produced by Friction Stir welding using CNC
vertical machining centre. The Brinnel hardness and tensile strength of the joints are considered for the investigation.
The results show that for optimal stir zone hardness, FSW parameter combination of 1200 rpm tool rotational speed,
10 mm/min welding speed and cylindrical tool profile should be used. For optimal joint tensile strength, the suitable
parameters combination is 1200rpm, 20mm/min and taper thread tool profile. From the investigation, it is concluded
that tool rotational speed is the major influencing factor for mechanical properties such as tensile strength and
hardness.