Evaluation of the influence of deep rolling on the mechanical properties of additively manufactured AlSi10Mg alloy

Deep rolling (DR) is a mechanical surface treatment widely employed to enhance the fatigue life of metallic components by inducing beneficial compressive residual stress states and increased surface hardness. The present study investigates the effects of DR in combination with heat treatments on the microstructure, porosity, and mechanical properties of additively manufactured AlSi10Mg. Specimens were produced via laser-based powder bed fusion (PBF-LB/M) and are characterized by at least 99.1 % relative density, confirmed by micro-computed tomography (mu-CT). Various heat treatments were applied: artificial aging (HT170), annealing (HT300), and a T6 treatment. Microstructural analysis revealed that heat treatments modified the silicon network within the aluminum matrix, significantly affecting mechanical properties. The as-built (AB) condition exhibits a fine silicon network, resulting in high tensile strength, however, limited ductility. HT170 preserves the network while the evolution of nanoscale precipitates is promoted; HT300 initiates network disintegration into coarser particles; finally T6 leads to complete dissolution, formation of silicon particles and iron-rich precipitates. DR significantly increases surface hardness and induces compressive residual stress states up to 1 mm depth. mu-CT analysis points at a reduction in defect size and density after DR, enhancing relative density and contributing to superior tensile strength and ductility. Tensile tests indicate that specimens deep-rolled at room temperature exhibit superior mechanical properties comparing all heat-treated conditions. These findings demonstrate the effectiveness of DR as a post-processing technique for enhancing the mechanical properties of additively manufactured AlSi10Mg components. Combining targeted heat treatments with mechanical surface modification allows tailoring of the microstructure and optimization of properties.