EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Synthesis of multi-metal hybrid structures represents a serious scientific and technological challenge. In this contribution, liquid dispersed metal powder bed fusion was used to fabricate a multilayered structure based on alternating Inconel 625 alloy (IN625) and 316L stainless steel (316L) layers on a 316L base plate. Analytical techniques revealed sharp compositional and microstructural boundaries between alternating ~60 µm thick alloys’ sub-regions as well as unique microstructures at different length scales. The periodic occurrence of IN625 and 316L sub-regions is correlated with a cross-sectional hardness increase and decrease and a compressive stress decrease and increase, respectively. The laser scanning strategy induced a growth of elongated grains separated by zig-zag grain boundaries. Chemical analysis indicates an intermixing of the alloy’s elements in the growth direction upwards at a morphologically sharp IN625-316L interface. A formation of reinforcing spherical chromium-metal-oxide nano-dispersoids demonstrates a possibility for reactive additive manufacturing at the nanoscale. The study shows that liquid dispersed metal powder bed fusion is an effective tool to combine dissimilar metallic alloys into unique hierarchical microstructures with synergetic properties.