Enhancing Wire Arc Directed Energy Deposition Outcomes Through Tailored Dwell Time Allocation

Abstract Wire Arc Directed Energy Deposition (WA-DED) is a metal 3D printing technique using a metal wire feedstock and an electric arc to build structures layer by layer. While effective, the high thermal energy involved introduces challenges like thermal accumulation, residual stress, and structural deformation. Dwell time, or pauses between layer depositions, is critical for managing these issues but can increase total build time. This paper presents a simulation study that explores strategies for enhancing WA-DED outcomes by designing interlayer dwell time allocation strategy without increasing the total time required to build parts. Using a thermally calibrated finite element model, a 6-layer single-wall structure of high-strength steel alloy (ERO120S-G) was simulated under four dwell time distribution scenarios for fixed total build times. Performance metrics evaluated include thermal accumulation (average nodal temperature), residual stresses (von Mises stress), and deflection. Results show that a dwell time strategy with shorter pauses in early layers and progressively longer pauses in subsequent layers minimizes thermal accumulation and residual stresses. In contrast, constant dwell time across layers results in higher stresses and thermal accumulation. Increasing the total build time further reduces stresses and thermal effects but causes greater deflection, highlighting a trade-off between thermal management and deformation. This work demonstrates that strategic dwell time allocation can optimize thermal and structural outcomes in WA-DED, enhancing performance and reliability without extending build time. These insights offer manufacturers practical guidelines for improving additive manufacturing processes.