Friction Stir Welding (FSW) is a materials joining process with great potential as joint quality is
exceptionally high and the process is very repeatable. These geometries are used extensively
in aerospace vehicles, in nautical vessels, and in pressure vessels. In this work, friction stir
welding is applied to the joining of two pipes, thin-walled, thickness variable hollow hemispheres.
The aim of this work determine the feasibility to weld two pieces of aluminum pipe by friction stir
welding process and study the effect on the mechanical properties of welding joints. Special
welding fixture fixed on conventional drilling machine has been conducted to attempt this welding
and group of welding parameters. The tool rotational speeds 485, 710, 910, 1120 and 1400 rpm
with a traverse speed 4mm/min were applied. The Mechanical properties of welded joints were
investigated using different mechanical tests including non destructive test (visual inspection)
and destructive test (tensile test, hardness and microstructure). Based on the stir welding
experiments conducted in this study the results show that aluminum pipe (6061) can be welded
by (FSW) process with a maximum welding efficiency (78.7%) in terms of ultimate tensile
strength, using 1400 (RPM) rotational speed, 4 (mm/min) traveling speed.