Prediction of In-Process Forces and Tool Durability in Stationary Shoulder Friction Stir Welding: A Process Modeling Approach

The conventional friction stir welding (FSW) of aluminum alloys is reasonably matured and most of the transportation industries integrated FSW in their production lines. The novel stationary shoulder friction stir welding (SSFSW) is a sister process of FSW, in which only tool probe rotates and linearly translates along the original weld joint interface to form a weld seam under much lesser heat input and lower peak temperature. The spindle torque and traverse force on the tool during SSFSW of a topical AA7075-T6 is important for the prior estimation of tool fracture but rarely reported in literature. An absolute comparison is made here between the SSFSW and FSW under the identical welding conditions using a finite element-based process model. The computed 3D temperature field, thermal cycle, spindle torque, traverse force, and tool durability index are reported here, and the model is thoroughly validated with the independent experimental results.