Effect of Laser Re-Melting Scan Strategy on Microstructure and Mechanical Properties of AlSi10Mg/SiC Composite Fabricated by Laser Powder Bed Fusion

In this study, SiC (10 vol%) reinforced AlSi10Mg (Al-10 mass%Si-0.35 mass%Mg) alloy matrix composites were fabricated by laser powder bed fusion (L-PBF) process. The effect of laser re-melting scan on densification behavior, microstructural formation and mechanical properties of the specimens was examined. The relative density of the specimens increased by applying re-melting scan, especially under the condition of a low input energy density less than 200 J/mm(3). No change was found in eutectic cell size in the microstructure of specimens by laser re-melting. On the other hand, the decomposition of SiC particles with corresponding formation of Al4SiC4 phase was enhanced and the hardness of the matrix region (excluding SiC particles) increased. A high ultimate compressive strength of 700 MPa was obtained when the composite was fabricated under an optimum building condition with re-melting scan due to the densification, a high volume fraction of SiC and fine microstructures. [doi:10.2320/jinstmet.J2023016]