Additive Manufacturing of Metal Components Using Concentric-Wire Laser Metal Deposition

Abstract

This work presents the development of the additive manufacturing process of large metal components based on concentric wire laser deposition technology. This technology is recognized as of great interest by the aeronautical sector as it would allow to reduce the cost of titanium components that currently require very expensive forging and machining operations. Experimentally, the different types of failure of the deposition process are shown, as well as the different stages of the process, starting with single-weld deposition and ending with the construction of regular solid geometries. A priori, wire deposition has structural advantages compared to metal powder deposition. This work focuses on the adjustment of the process from a macroscopic and merely geometric point of view prior to the microstructural and properties analysis foreseen in future works. Keywords: Laser Metal Deposition, Wire, Concentric, Cladding, Additive manufacturing, 3D printing

A Review on Wire-Laser Directed Energy Deposition: Parameter Control, Process Stability, and Future Research Paths

“…The laser beam irradiance or intensity inversely correlates with the focal spot size since it is defined as the power per unit area. As the experimental research suggests, once the wire diameter is selected, the diameter of the laser beam can be set nearly the same as the wire diameter to ensure the accurate positioning of the heat source around the wire [56,89,90].…”

“…Coaxial W-LDED represents a valuable enhancement to the existing processes, offering a directional independent method with high deposition rates and precision [72,118,119]. Unlike lateral deposition heads, the use of concentric or coaxial heads (Figure 9a) eliminates the need for table or head rotation, allowing material deposition in virtually any direction [73,89,120]. Specialized optics have been developed to shape the laser beam in a way that enables wire feeding through the center of the beam to ensure a distribution of laser radiation over the wire [121][122][123].…”

“…Low dilution is generally preferable as it indicates minimal mixing of the substrate with the fed wire, leading to a more stable and reliable process (Figure 12a). In contrast, high dilution can result in poor bead appearance and increased susceptibility to defects such as pores and cracks (Figure 12b) [58,89]. dilution is essential for producing high-quality weld beads with the desired properties and structural integrity [125,133].…”

“…Low dilution is generally preferable as it indicates minimal mixing of the substrate with the fed wire, leading to a more stable and reliable process (Figure 12a). In contrast, high dilution can result in poor bead appearance and increased susceptibility to defects such as pores and cracks (Figure 12b) [58,89]. As demonstrated in Equation ( 7), dilution is calculated based on the ratio of the penetration area into the base material (i.e., A ) to the total area of deposited material (i.e., A +A ) in the cross-section of the bead [34,54,134].…”

“…As shown in Figure 13a, a low aspect ratio suggests that the bead is taller compared to its width, whereas a high aspect ratio indicates a flatter weld bead, meaning it is wider relative to its height [62,102,137]. In the literature, it is suggested to aim for beads with an aspect ratio higher than three to ensure the formation of defect-free beads with a favorable appearance [89,139]. Similar to the dilution degree, the aspect ratio showed a direct correlation with laser power and TS while having an inverse correlation with WFS under various conditions [39,58,125].…”