Design methodology for functionally graded materials: framework for considering cracking

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 deleterious phases, or buildup residual stresses. This study builds on our previously proposed concept three-alloy FGM system feasibility diagrams for identification gradient pathways that avoid phases in FGMs by also considering hot cracking. Here, five cracking criteria were integrated into diagrams, and equilibrium simulations carried out based Scheil results (termed hybrid Scheil-equilibrium simulation) predict phase below solidus temperature solidification microsegregation. The new applied four studied systems, newly approach predicted high crack susceptibility, detrimental formation, BCC experimentally observed region. demonstrates utility framework prediction design future pathways.