Additive manufacturing (AM) processes are gaining an impressive and growing attention owing to their ability to fabricate near-net shape components with complex geometries. Laser powder bed fusion (L-PBF) is one the most widely employed AM techniques since it can work with a wide range of metallic materials. Although parts with relatively high surface quality and bulk density can be manufactured by employing optimised L-PBF parameters, there are still process-induced imperfections, e.g. defects and relatively high residual stresses that can affect structural integrity of the components especially under fatigue loading.
This project aims at investigating the effect of process and post-process induced microstructures, defects and residual stresses on fatigue cracking behaviour of austenitic stainless steel 316L produced via L-PBF. Fatigue tests are carried out to study initiation and propagation of cracks in specimens fabricated in different build directions. Predictive models are developed for fatigue life assessment contributing to qualification and certification of safety-critical AM components.