Ad Hoc Heat Treatments for Selective Laser Melted Alsi10mg Alloy Aimed at Stress-Relieving and Enhancing Mechanical Performances

The response of an AlSi10Mg alloy produced by selective laser melting (SLM) to specifically designed heat treatments is explored. Thermal phenomena of the rapidly solidified material were studied by differential scanning calorimetry (DSC), and the results have been used to define specific post-processing thermal treatment temperatures. In detail, three heat treatments were studied: two innovative ones, able to selectively trigger (1) Mg2Si precipitation and (2) the rupture and spheroidization of the silicon network, and (3) a T5-like aging were applied for different times and their effects on mechanical properties were studied. The first and the second heat treatments were selected by combining DSC analysis and aging curves for the optimization of the temperature and duration. And these were more deeply investigated in terms of microstructural evolution and of residual stresses. The optimized thermal treatments for SLM-built AlSi10Mg are recommended as valid alternatives to the usually applied T6 or high-temperature stress release treatments.