Improving fatigue performances of selective laser melted A1-7Si-0.6Mg alloy via defects control

The relationship between defects and mechanical properties, especially fatigue properties, of selective laser melted (SLMed) Al-7Si-0.6Mg alloy built with different processing parameters has been investigated. With relatively high densities, although the tensile strength is not affected, ductility and fatigue properties vitally vary with different defects. Furthermore, an excellent fatigue performance with the run-out stress of 200 MPa has been achieved with optimised processing parameters, which is by far the best fatigue performance in SLMed Al-Si alloys. Microstructure and fractography are characterised by different methods, demonstrating that defects and Si particles are the main controlling factors for the fatigue properties.