Friction stir processing of additive manufactured AlSi10Mg parts to improve mechanical behaviour

Additive manufactured (AM) and, more specifically, selective laser melt (SLM) parts have huge potential in many fields and industries. However, some applications, such as structural components in the aerospace industry, require a combination of properties that is currently not achievable through AM alone. Aluminium alloys processed by SLM often present porosity and anisotropy, reducing ductility and notably compromising resistance to fatigue. In order to locally improve mechanical behaviour of these SLM parts, a post-processing solution is devised through the use of friction stir processing (FSP). Thanks to this method, porosity has been eliminated and ductility increased on SLM AlSi10Mg samples. FSP modifies and homogenizes the SLM microstructure. The process also affects the damage and fatigue failure mechanism, bringing an enhancement of fatigue strength. In view of these first results, FSP appears as an attractive option to improve performance of AM parts, especially considering the possibility of combining or implementing this method into the normally necessary machining step