Impact of In-Process Thermal Management Strategies in Wire Arc Additive Manufacturing on Residual Stress

Wire Arc Additive Manufacturing (WAAM) allows for cost-effective and sustainable production of large volume, complex metal parts using high deposition rates. However, the cyclic heat input impacts material properties and results in long process times. Previous studies have shown that thermal management strategies involving both external heating and cooling can help to homogenize and control the material properties, increase the process efficiency and favorably affect the part geometry. Moreover, the changes in the temperature profiles influence the resulting residual stress state.

In order to analyze the impact of different in-process heating and cooling methods on the residual stresses, high-strength steel samples are built by WAAM using in-process thermal management strategies. The mechanical properties are characterized, and the residual stresses are analyzed experimentally for each state and compared to each other. Furthermore, finite element simulations are performed for gaining information on the residual stresses in the whole sample. The study concludes with recommendations how thermal management strategies can be used to control the residual stress state in WAAM.