Effect of Travel Speed on Microstructure Evolution of Cold Metal Transfer with Pulse Wire Arc Additive Manufacturing AA2024

This study investigates the effect of arc travel speed (TS) on molten pool morphology, grain structure, crystallographic texture, and grain boundaries in cold metal transfer with pulse hybrid wire arc additive manufacturing of AA2024 alloy. Deposits are fabricated at TS of 7.2, 7.9, and 8.6 mm s −1 . Electron backscatter diffraction is used to examine grain orientation, size, and dislocation distribution in the molten pool zone (MPZ), molten pool boundary zone (MPB), and molten pool transition zone (MTZ). Porosity varies nonmonotonically with TS, reaching a minimum at 7.9 mm s −1 . Higher TS reduces heat input and accelerates droplet transfer, producing flatter pools with finer, more uniform grains. Grain size decreases and equiaxed fraction increases in MPB and MPZ, while equiaxed formation becomes more pronounced in MTZ. Q and U textures weaken with higher TS; MTZ exhibits increased low‐angle grain boundary density; and Σ3 boundary fraction peaks at 7.9 mm s −1 , indicating strain energy release and reduced grain deformation. Tensile properties improve with TS, reaching 289.1 MPa ultimate tensile strength and 11.6% elongation at 8.6 mm s −1 . Anisotropy results from grain refinement, higher equiaxed fraction, weakened texture, and low porosity.