AbstractFriction surfacing (FS) is a solid state coating technology for similar and dissimilar metallic materials. The coating of the substrate with a consumable material is enabled due to frictional heat and plastic deformation and is performed below the materials' melting temperature. In this work, the spatio-temporal temperature field during FS is investigated within the substrate via a combined experimental-numerical approach. The study presents a robust and efficient thermal process model accounting for the contributions of friction and plasticity as heat input. The geometry of the applied heat source is dependent on the deposit geometry and the evolving flash. Extensive spatial temperature measurements for a dissimilar aluminum alloy combination are used in order to identify the required input parameters and to validate the model. The process temperature profiles for varied process parameters, such as axial force, rotational speed and travel speed as well as substrate thickness and backing plate material are systematically investigated, where experimental and numerical results are in good agreement. Deviations are in particular associated with possible experimental scatter and unknowns regarding the exact position of the measurement as well as modeling assumptions in terms of the heat source geometry. Overall, the detailed comparisons illustrate that the developed numerical model is able to obtain the temperature evolution and distribution during FS deposition with acceptable accuracy for a wide range of process conditions.