Defects as a root cause of fatigue weakening of additively manufactured AlSi10Mg components. (August 2020)

• Record Type: Journal Article
• Authors: Ferro, Paolo; Fabrizi, Alberto; Berto, Filippo; Savio, Gianpaolo; Meneghello, Roberto; Rosso, Stefano
• Is Part Of: Theoretical and applied fracture mechanics. Volume 108(2020)
• Publication Date: 2020-08
• Subjects: Laser powder bed fusion -- Additive manufacturing -- ALSi10Mg -- Fatigue strength -- Fractography -- Porosity; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2020.102611
• Languages: English
• ISSNs: 0167-8442

Abstract

Graphical abstract: Highlights: Fatigue strength was found insensitive to the build relative to scraper direction. Fatigue strength is highly sensitive to porosity morphology, size and distribution. In most cases, lack of fusion was the killer defect. Abstract: Additive manufacturing is an emerging technique that is not only subjected to the interest of academic world because of its peculiar characteristics to obtain new material properties and optimized 3D geometries, but it also finds the interest of the industrial sector because of the possibility to build advanced components never realized until now. Among the additive manufacturing processes, Laser Powder Bed Fusion process is perhaps the most used in producing components out of metallic materials. In particular, thanks to its low density and its hypoeutectic favourable composition, AlSi10Mg alloy is particular suitable for the production of lightweight components by additive manufacturing. However, for safety reasons, their mechanical, static and cyclic, characteristics need to be well understood and predicted. Unfortunately, they are dramatically influenced by process parameters that in turn may promote killer defects dangerous for the fatigue strength of load bearing mechanical components. This contribution is aimed at highlighting the influence of defects on the fatigue resistance of AlSi10Mg samples produced by laser powder bed fusion. The combination of process parameters were obtained that maximizes the fatigue strength and reduces the scattering of the results.