Selective laser melting of AlSi10Mg alloy: Process optimisation and mechanical properties development

• Statistical design of experiment approach and the energy density model were correlated for SLM of AlSi10Mg alloy.
• The mechanical properties were assessed, including the high temperature creep properties.
• The energy threshold for processing AlSi10Mg alloy are within the range 60–75 J/mm3.

The influence of selective laser melting (SLM) process parameters (laser power, scan speed, scan spacing, and island size using a Concept Laser M2 system) on the porosity development in AlSi10Mg alloy builds has been investigated, using statistical design of experimental approach, correlated with the energy density model. A two-factor interaction model showed that the laser power, scan speed, and the interaction between the scan speed and scan spacing have the major influence on the porosity development in the builds. By driving the statistical method to minimise the porosity fraction, optimum process parameters were obtained. The optimum build parameters were validated, and subsequently used to build rod-shaped samples to assess the room temperature and high temperature (creep) mechanical properties. The samples produced using SLM showed better strength and elongation properties, compared to die cast Al-alloys of similar composition. Creep results showed better rupture life than cast alloy, with a good agreement with the Larson–Miller literature data for this alloy composition.