Laser Direct Energy Deposition (DED) enables the fabrication of functionally graded metal alloys, offering great potential for advanced applications in aerospace, energy, and biomedical fields. However, combining metals with different thermal and mechanical properties poses significant challenges, often leading to cracking and brittle intermetallic phases. This study investigates the fabrication of a functional gradient between stainless steel 316L and Inconel 625, two alloys with good miscibility except in specific compositional ranges where segregation and embrittlement may occur.

A key aspect of this research is the evaluation of different powder batches, as even materials with the same nominal composition can produce distinct results due to minor elemental variations. The influence of these variations on phase formation, microstructure, and mechanical integrity is analyzed in detail. Additionally, the feasibility of introducing a third alloy as a buffer layer is explored, following an approach similar to welding techniques. This intermediate layer aims to improve material compatibility, reducing defect formation and enhancing the structural performance of the gradient region.

The findings provide valuable insights into the behavior of functionally graded structures and contribute to the optimization of multi-material Laser DED processes. This research highlights strategies to mitigate fabrication challenges and expand the applicability of functionally graded materials in high-performance industries.