Additive manufacturing (AM) by selective laser melting (SLM) of aluminum alloys has received great attention due to their improved mechanical properties compared to as-cast alloys, for applications such as aerospace and nuclear industries.
This study examines the effects of radiation damage on the unique microstructure and mechanical properties of SLM AlSi10Mg alloy. The alloy was implanted with helium ions at different energies (425,500,575 keV) at room temperature to produce a damaged surface layer. The microstructure was examined by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanical behavior was studied using nano-indentation.
It was found that SLM produces a fine hierarchical microstructure, consisting of primary Al surrounded by Al-Si eutectic and decorated with Si particles. Through-focus imaging in the TEM revealed the accumulation of He into bubbles of different density and size within the different phases. This was correlated with the mechanical properties of each phase and the overall mechanical behavior of the alloy. The results were also compared to as-cast AlSi10Mg.