Friction stir welding (FSW) is a relatively new welding process that may have significant
advantages compared to the fusion processes as follow: joining of conventionally non-fusion
weldable alloys, reduced distortion and improved mechanical properties of weldable alloys
joints due to the pure solid-state joining of metals. In this paper, a two-dimensional model
based on finite element analysis is used to study the thermal history and thermomechanical
process in the butt-welding of aluminum alloys. The model incorporates the mechanical
reaction of the tool and thermomechanical process of the welded material. The heat source
incorporated in the model involves the friction between the material and the probe and the
shoulder. The calculation result also shows that preheat to the workpiece before process is
beneficial to FSW. The effects of welding parameters such as preheating (100, 200) °C,
rotational speed (960, 1200) rpm and linear speed (110, 155, 195) mm/min on the distribution
of temperature of Al Alloy will be studied.