One of the main problems in friction stir welding (FSW) is the non-uniform distribution of the properties in the weld area. The most important factor influencing the properties of the produced joint is the temperature.
An analytical heat source model of FSW was improved by taking into account not only the friction at the contact surfaces or close to the contact surfaces under the tool shoulder and at the tool probe sides but also the influence of the plastic deformation in the weld nugget and translation motion of tool on heating of the workpiece.
The value of heat input generation depends on the tool geometry, welding parameters and material properties. Asymmetric heat source is the result of the combination of rotation speed and translation motion.
The temperature was measured using thermocouples.
The finite element model was used to define the temperature distribution.
The results of the simulation are in good agreement with experimental results.
Heat flow during the FSW is directed to the backing plate so backing plate has great influence on the temperature distribution, i.e. material and the contact between the backing plate and workpiece.