|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Additive Manufacturing Fatigue and Fracture V: Processing-Structure-Property Investigations and Application to Qualification
||High Cycle Fatigue and High Temperature Creep Behaviors of Selective Laser Melted CrMnFeCoNi High-entropy Alloy Strengthened by In-situ Formed Oxide
||Young-Kyun Kim, Sangsun Yang, Kee-Ahn Lee
|On-Site Speaker (Planned)
In-situ formed oxide reinforced CrMnFeCoNi high-entropy alloy (HEA) was additively manufactured by selective laser melting (SLM), and its microstructure, fatigue and creep behaviors were systemically investigated. SLM-built HEA shows heterogeneous grain structure as well as sub-structure decorated by dislocations. In particular, nano-sized oxides were evenly distributed at the sub-structure boundaries due to the high oxygen content in the pre-alloyed powders. SLM-built HEA reveals exceptional creep resistance at 600 °C, as compared to other HEAs, and stress exponents of n = 3.45 and n = 6.45 for low stress region (LSR) and high stress region (HSR), respectively. This indicates that the creep mechanisms of SLM-built HEA were viscous glide at the LSR and dislocation climb at the HSR. The S-N curves reveals that SLM-built HEA has extraordinary resistance to HCF (fatigue limit of 570 MPa) compared to homogenized HEA. Based on the above findings, creep and fatigue mechanisms were also discussed.