Heat treatment optimization via thermo-physical characterization of AlSi7Mg and AlSi10Mg manufactured by Laser Powder Bed Fusion (LPBF)

The current paper aims at unraveling the threefold interrelationship between process, microstructure and properties of two materials, AlSi7Mg and AlSi10Mg, processed by laser powder bed fusion (LPBF) on a 3D Systems ProX® DMP 320, and subsequently heat treated under different conditions in argon atmosphere. Three thermo-physical characterization techniques were employed to monitor microstructural and concomitant mechanical property changes during heat treatment of LPBF processed Al-Si-Mg based alloys. The evolution of dissolved Si in the FCC Al matrix was monitored by electrical resistivity (ER) measurements, precipitation reactions were monitored by combining differential scanning calorimetry (DSC) with elastic property and damping measurements using the impulse excitation technique (IET). The evolution of the microstructure upon heat treatment was linked to characteristic phenomena captured by each of the three thermo-physical characterization techniques. Finally, the evolution of internal and residual stresses of both processed alloys upon heat treatment was monitored via the cantilever method.status: publishe