New Ni-based superalloys designed for laser additive manufacturing

To balance the relationship between weldability and properties, a series of Ni-based superalloys with varying amount of Cr-like elements were designed using a cluster-plus-glue-atom model, and fabricated by laser additive manufacturing (LAM). The microstructure of the as-deposited superalloys consists of few topological close packet (TCP) phases distributed between gamma-Ni dendrites with epitaxial growth characteristic. With the increase of Cr-like elements amount, TCP phases change from granular Laves phase to long-striped Laves phase plus acicular sigma phase, and exhibit a trend of first decreasing and then increasing in amount. The mechanism for such microstructure evolution was analyzed. Performance tests reveal that the NiCrlike-2 alloy (Ni54.8Fe20.3Cr17.3Mo1.50Al1.56 Nb3.47Ti1.22 at.%), which has the fewest amount of TCP phases, presents a novel combination of strength, ductility, high temperature oxidation-resistance, and good weldability. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

By adjusting the content of Cr-like elements, the balance between the performance and weldability of Ni-based superalloys can be improved, reducing the impact of TCP phases on material performance and enhancing the overall performance of the alloy.