| Abstract Scope |
Wire arc directed energy deposition (DED-Arc) process is increasingly attempted for layer-by-layer fabrication of large, near net shape metallic components due to its high deposition rate and flexibility to automation. The ongoing attempts to adopt DED-Arc process for versatile applications are notably dependent on the finite element and finite volume method based numerical simulation models, which are used to compute the transient temperature field, cooling rate, and melt track dimensions for a given DED-Arc process conditions. Although these models have helped in basic mechanistic understanding, they struggle enormously due to massive computational demand.
We propose here a three-dimensional analytical heat conduction model with temperature-dependent material properties and volumetric heat source to compute the transient temperature field and reconstruct the DED-Arc deposit profiles reliably and rapidly. The model is validated against experimentally measured results for DED-Arc of multiple filler wire alloys, and a range of process conditions. Most importantly, the analytical model can simulate the temperature field several orders of magnitude faster than the contemporary numerical simulation models.
Building on this foundation, the present work proposes further to use the analytical model as a forward evaluator within a parametric design space for identifying suitable process conditions and scanning strategy for part-scale DED-Arc. The analytical model in conjunction with suitable defect predictor metrics can help design part-scale DED-Arc, and select the process condition and scanning strategy. In turn, a seamless generation of the robot code for final printing can be achieved rapidly. Overall, this work demonstrates, through a set of scanning strategy and process parameter combinations, that the analytical framework can meaningfully narrow the design space and serve as a substantive off-line design tool for part-scale DED-Arc. |