70 - Designing fatigue-resistant Additively-Manufactured components: from understanding damage mechanisms in common metallic alloys to establishing a reliable fatigue assessment methodology
Abstract
Utilizing additive manufacturing (AM) for load-bearing metal components in the industry presents a primary challenge due to the relatively low fatigue strength and significant variability inherent in as-built parts. Multiple variables strongly influence fatigue resistance, including the presence of defects, residual stresses, and process-induced anisotropy. To ensure robust component design, it is crucial to thoroughly analyze and control these sources of variability and incorporate them into a proper fatigue strength assessment framework. The objective of this presentation is to provide a comprehensive overview of the key factors affecting the fatigue life of AM components, with a specific focus on the Laser-powder bed fusion process (L-PBF), and to introduce a reliable fatigue life methodology for their proper consideration. In the initial part of the presentation, the fatigue failure mechanisms of typical metallic alloys commonly employed in the L-PBF process, such as AlSi10Mg, CP1, Ti6Al4V, Inconel, and CrCo, will be delved into. Special attention will be paid to volumetric and surface features, including roughness. Furthermore, the impact of residual stresses on the fatigue life of AM components will be discussed. The second part of the presentation will discuss assessment strategies based on the damage tolerance approach, emphasizing their formulation based on the previously defined damage mechanisms. The unique characteristics of the AM process, including orientation dependency, defects, and residual stresses, can be properly accounted in a fracture-mechanics framework, and this will be shown to ensure the design of reliable components. In the final part, a concise examination of common non-destructive techniques (NDTs), such as X-ray computed tomography and co-focal microscopy, will be provided. The integration of NDT findings with fatigue models can aid the industry in establishing criteria for defect acceptability, enhancing the overall quality and reliability of AM components.
Speaker
Luca Patriarca
Discover speaker profilePolitecnico di Milano, Milano, Italy
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70 - Designing fatigue-resistant Additively-Manufactured components: from understanding damage mechanisms in common metallic alloys to establishing a reliable fatigue assessment methodology
Date/Time
20/03/2024
3:30 pm -4:00 pm
Location
Room 6