Modulating the damping capacity of SLMed AlSi10Mg trough stress-relieving thermal treatments

In the Additive Manufacturing (AM) field, Selective Laser Melting (SLM) process is one of the most promising manufacturing technologies for the production of 3D complex parts. High-tech sectors, like aerospace, show growing interest for the use of AM, because it can offer unique opportunities in terms of freedom in the design and integration of some specific functionalities in lightweight structures. Together with lightness of materials, another important requirement is the capacity of vibrations damping, relevant e.g. for the vibro-acoustic environment during launch in the aerospace field. This work focuses on the correlation between the damping behavior of AlSi10Mg specimens and residual stresses induced during SLM, i.e. in as-built condition, or after different post-additive heat treatments, specifically studied for this Al alloy. Indeed, residual stresses have a well-known influence on the static and fatigue mechanical behavior, but a few literature works are present relating residual stresses with damping capacity. Results of the performed experimental tests showed that the damping capacity decreases with the increase of the heat treatment temperatures, i.e. damping can be modulated by customized thermal treatments.