Effect of Annealing Heat Treatment on the Macroscopic and Microscopic Deformation Behavior of Additively Manufactured AlSi10Mg Alloy

The additively manufactured AlSi10Mg alloy demonstrates considerable residual stresses, adversely affecting the dimensional accuracy, operational safety, and corrosion resistance of the parts. In practical applications, stress relief annealing is necessary to eliminate residual stresses in residual stresssensitive applications. However, the current understanding of the mechanical properties of the additively manufactured AlSi10Mg alloy after annealing is still limited to the macroscopic level. To further investigate the micromechanical behavior and intrinsic mechanisms of the alloy, this study employed synchrotron Xray diffraction technology to conduct in situ deformation analysis. This study thoroughly examined the lattice strain and stress evolutions of the Al and Si phases and clarified the individual contribution of each phase to the strain hardening rate of the alloy. In addition, this study quantitatively assessed the evolution of dislocation density and elucidated the influences of annealing heat treatment on the load transfer and dislocation behavior of the additively manufactured AlSi10Mg alloy.