Advances in Wire-Laser Metal Deposition: Bimetallic Fabrication, Defect Mitigation, and Future Directions

Wire-Laser Metal Deposition (W-LMD) is a transformative additive manufacturing technology that utilizes a laser heat source to melt metallic wire feedstock for the high-efficiency fabrication of large-scale, near-net-shape components. The technology is distinguished from other manufacturing processes due to its high material utilization efficiency and superior safety compared to metal powder-based systems. W-LMD systems are composed of a focused laser, a wire feeder mechanism, a multi-degree of freedom motion system, cooling system, and a shielding gas supply to prevent oxidation. Deviation in process parameters of the system components can lead to external defects such as stubbing (insufficient melting) and dripping (melting above the melt pool), or other forms of internal defects such as porosities. A key feature of W-LMD systems is their capability of fabricating bimetallic structures. This paper reviews key studies on W-LMD systems and their advancements in bimetallic fabrication. The review highlights the current gaps and required research work in the field for bimetallic W-LMD manufacturing and its significance.