Fatigue and Fracture Reliability of Additively Manufactured Al-4047 and Ti-6Al-4V Alloys for Automotive and Aerospace Applications

Abstract

Metal additive manufacturing is at a stage that it can now be used not only for rapid prototyping but for rapid manufacturing of functional components as well. However, for the reliable employment of parts, their mechanical performance is an important parameter not only in terms of their quasistatic strength but their fatigue performance for dynamic applications. Their fatigue performance should be at par with that of conventionally manufactured alloys. There can still be reliability issues for the additively manufactured parts, as the specific issues—remnant porosity, surface finish, residual stresses, and fatigue scatter—are influenced by the selected process parameters. This paper presents the state-of-the-art of fatigue performance for additively manufactured Al-4047 and Ti-6Al-4V and ways to improve and manipulate the part properties. The results show that their mechanical performance is comparable, even better in some cases, to that of conventionally manufactured materials if appropriate processing parameters and post-processing techniques are employed.