A new thermal model in SAE-AISI 1524 friction stir welding

Several important key problems and issues remain to be addressed about the numerical analysis of friction stir welding. The main feature of the thermal numerical approach is to accurately compute the thermal distribution produced by the friction between the plate and the tool. It is well known that the downward force applied from the tool creates a distributed pressure between the shoulder and the workpiece. Based on this, a new expression to represent the heat generation in FSW is proposed. Results of thermal cycles, thermal histories, and shapes of the weld and HAZ obtained with the proposed expression in SAE-AISI 1524 carbon steel are presented. Results demonstrate that the energy input is strongly dependent on the tool advance speed, rotational speed, and the axial pressure necessary to produce yielding. For instance, at a constant increase in axial pressure, lower peak temperature increments are produced when higher tool advance speeds are chosen. The mathematical modeling has been investigated with a view to generate numerical data to provide values for further assessment and experimental comparison.