On the processability and mechanical behavior of Al–Mg–Sc alloy for PBF-LB

The use of Al–Mg–Sc alloys has experienced a remarkable increase for the additive manufacturing industry, especially in aerospace. Al–Mg–Sc shows an outstanding behavior with much higher mechanical performance in both static and fatigue with respect to other alloys for powder bed fusion laser-based (PBF-LB) process like AlSi10Mg or AlSi7Mg. Alloy composition in commercially powder suppliers has been modified from that available in 2013 to a new version in 2017, and, therefore, further information on its processability and performance is still required. Furthermore, the mechanical behavior after different post-processes needs to be analyzed to set the best combination of e.g. thermal treatments and surface finishing qualities. This paper reports on the mechanical behavior of Al–Mg–Sc PBF-LB alloy. Its processability is demonstrated by the development of a design of experiments campaign for achieving the best processing parameters. Samples for static and fatigue tests have been manufactured, which have been subjected to stress relieve treatments or hot isostatic pressing, but also with different surface qualities (machined or sand blasted). Finally, the influence on the mechanical static properties in the alloy with respect to the building position has been investigated and related to the argon flow direction.