Additive manufacturing of fatigue resistant austenitic stainless steels by understanding process-structure–property relationships

Abstract

The limited understanding of additive manufacturing process-structure–property inter-relationships raises some concerns regarding the structural reliability, which limits the adoption of this emerging technology. In this study, laser beam-powder bed fusion is leveraged to fabricate an austenitic stainless steel with a microstructure containing minimal known crack initiation features. Ex-situ microstructural observations of the crack initiation features and mechanisms are carried out for interrupted fatigue tests via electron backscatter diffraction mapping of the micro-cracks. Results show that the additive manufactured stainless steel alloy has improved fatigue resistance compared to its wrought counterpart as a result of the unique microstructural features.

Keywords

• laser beam-powder bed fusion
• crack initiation
• microstructure
• twin boundary
• cyclic deformation