  In functionally graded materials (FGMs) fabricated using directed energy
deposition (DED) additive manufacturing (AM), cracks may form due to
interdendritic stress during solidification, the formation of intermetallics,
or the buildup of residual stresses. This study builds on our previously
proposed concept of three-alloy FGM system feasibility diagrams for the
identification of gradient pathways that avoid deleterious phases in FGMs by
also considering solidification cracking. Here, five solidification cracking
criteria were integrated into the feasibility diagrams, and equilibrium
simulations were carried out based on Scheil results (termed Scheil-equilibrium
simulation) to predict phase formation below the solidus temperature
considering solidification microsegregation. The new feasibility diagrams were
applied to four previously studied FGM systems, and the newly proposed approach
predicted high crack susceptibility, detrimental phase formation, or
interdendritic BCC phase formation in the experimentally observed cracking
region. This demonstrates the utility of the proposed framework for crack
prediction in the design of future FGMs gradient pathways.
