Optimization and characterization of C103 Nb alloy fabricated by laser wire directed energy deposition

Although there is growing interest in manufacturing refractory components using additive manufacturing techniques, powder-based additive manufacturing processes face challenges due to the difficulty of powder production. This study aimed to optimize the process and evaluate the tensile properties of C103, a representative Nb alloy, using Laser Wire Directed Energy Deposition (LWDED) for the first time. The results revealed that a uniform melt pool did not form at laser powers below 2000 W, while at powers exceeding 2600 W, the laser beam caused premature wire melting due to reflection, preventing proper deposition. In the fabricated samples, Hf, a key constituent of C103, reacted with atmospheric oxygen during the deposition process, forming HfO₂ at the solidification cell boundaries. The oxygen content increased with higher laser power and vertical sample height. Tensile testing showed that the yield strength exceeded the ASTM B654 standard by more than 10 %. Our findings suggest that LWDED is an efficient and effective technique for manufacturing refractory components.