Designing Against Failure in Additive Manufacturing: From Fracture in Monolithic Samples to Designing Functionally Graded Materials

To adopt metallic materials made by additive manufacturing (AM), it is critical to understand, and design against fracture, particularly under complex stress states accessed in service, and with the possible presence of internal pores. Additionally, when designing functionally graded materials (FGMs) in which composition is deliberately varied with position within a component to result in spatially tailored properties, it is critical to avoid deleterious phase formation and solidification cracking during fabrication. This talk will describe our approach for studying the combined effects of stress state and internal pores on the fracture behavior of stainless steel 316 and Ti-6Al-4V manufactured using laser powder bed fusion AM, providing a pathway for designing against failure under realistic conditions. Additionally, it will describe our framework for considering deleterious phase formation and crack susceptibility when designing compositional pathways for FGMs, and more broadly, compositions amenable to AM in general.