Interrupted metal deposition wire arc additive manufacturing to fabricate objects with trailered microstructures

Abstract

Advances in additive manufacturing have enabled innovative approaches to creating materials with tailored properties. This study presents Interrupted Metal Deposition in Wire Arc Additive Manufacturing (IMD-WAAM) for fabricating thin walls of Functionally Graded Materials (FGMs). By controlling heat input during deposition, IMD-WAAM precisely modulates microstructural evolution. Characterization techniques, including Optical Emission Spectroscopy (OES) for composition analysis, Field Emission Scanning Electron Microscopy (FESEM), and Electron Backscatter Diffraction (EBSD) for grain-level insights, along with Continuous Cooling Transformation (CCT) diagrams from JMatPro, revealed distinct microstructural zones. Continuous deposition showed coarse ferritic structures, while a 5-second Inter-Drop Cooling Time (IDCT) produced refined ferritic and bainitic structures. These results demonstrate IMD-WAAM's ability to achieve seamless property gradation, making it a transformative method for aerospace, biomedical, and other applications requiring customized material properties. © 2025 Elsevier B.V.