Process stability and deposition behavior of branch wire coupled arc-DED

Higher deposition rate and lower remelting are goals for arc-directed energy deposition (arc-DED). This study presents a variant of arc-DED, where an external wire separates partial currents from a leading arc to generate a branch arc. The angle between leading and branch wires, branch wire extension, and distance from both wires’ intersection to substrate surface are examined to identify optimal conditions. More stable and productive deposition is achieved at a 45° wire angle, 22 mm extension, and 0 mm intersection distance. Increasing branch current from 0 to 90 A reduces dilution rate from 34% to 8.4%, decreases bead width by 35.2%, and increases bead height by 88.5%. The wall fabricated at a branch current of 60 A exhibits finer mid-section grains and shows 4.4% higher tensile strength and 11.7% greater elongation than its GMA-DED counterpart. The variant is feasible to gain high-productivity and low remelting parts with better mechanical properties.