Fatigue performance in additively manufactured metal alloys

The paper provides a comprehensive review on the fatigue characteristics of additive manufactured metal alloys, exploring key factors that influence their durability and underlying failure mechanisms. In addition, the article examines various fatigue mechanisms that can occur in AM metals subjected to cyclic loading, including the initiation and propagation of cracks and fracture mechanics. The effects of the feedstock powder characteristics, print defects, microstructure, build orientation, surfaces finish, residual stresses, sample size and geometry, and the consequences of heat treatment and thermal post-processing are examined in detail. The main focus is on powder bed fusion processes, but relevant papers on wire arc additive manufacturing and other metal AM processes were also included in the review. This work provides readers with a comprehensive understanding of the underlying difficulties and potential benefits of fatigue analysis in AM-processed metal alloys. It will also help readers to systematically identify future research problems, gaps, challenges, and promising future directions in the fatigue performance of AM metal alloys.