Numerical and Experimental Study on the Temperature Field of Additive Friction Stir Deposition

Additive friction stir deposition (AFSD) is an emerging solid-state additive manufacturing technology. AFSD can create freeform and fully-dense structures without melting and solidification making it promising as an alternative to fusion-based metal additive manufacturing technology. The feedstock is plasticized by the heat of plastic deformation and friction, and the deposit layer is formed by the squeezing of the tool shoulder. The heat input during AFSD significantly affects the surface quality, microstructure, and mechanical properties of the deposited layer. Based on the temperature field variation characteristics of AFSD, which can be divided into two stages, the first stage is the preheating stage and the second stage is the steady deposition stage. As such significant differences in the heat distribution and conduction mechanisms between the two stages, the friction preheating heat source model and steady deposition heat source model are established respectively. The finite element numerical simulation method is used to calculate the AFSD temperature field and to analyze the heat generation mechanism, heat conduction pattern, and distribution characteristics of the temperature field during the preheating stage and steady deposition stages. The experiments are designed to verify the difference in the simulation and experiment temperature, where experimental and numerical results are in good agreement.