Low temperature annealing dedicated to AlSi10Mg selective laser melting products

In this work a new heat treatment specific for selective laser melted (SLM) AlSi10Mg products is studied. Samples were analyzed by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM); two exothermic phenomena were recognized, kinetically analyzed and associated to the precipitation of Mg2Si and to the rupture and spheroidization of the silicon network, which is characteristic of SLM built parts. Thermal treatments, based on the results of calorimetric analyses, were defined and applied to SLM built samples. The evolution of the silicon network morphology was confirmed by SEM observations and corresponding hardness variations were correlated to the treatment conditions. Dedicated thermal treatment is therefore proposed as a lower temperature alternative to the usually applied post - building annealing.