Microstructure and Tensile Properties of Selective Laser Melting AlSi10Mg Alloy

AlSi10Mg alloy tensile samples were fabricated by selective laser melting equipment (SLM100) under different laser powers and scanning speeds. The microstructure of the molded samples was observed with Olympus BX5 optical microscope and JEOL JSM-6490LV scanning electron microscope. The effects of laser power and scanning speed on the tensile properties of the samples were investigated. The results show that microstructures of the molded samples are fish scale and elongated cells parallel to the stacking direction, which are overlapped and have fine dendritic cells. When the laser power reaches 190 W, the tensile strength of the sample increases with the decrease of the scanning speed. When the scanning speed is set to be 800 mm/s, the tensile strength is up to 371 MPa. The tensile strength increases with the increase of the laser power at the fixed scanning speed. The fracture mechanism of the tested samples is proved to be quasi-cleavage fracture. At the same line-energy, the tensile strength of the tested sample reaches as high as 451 MPa with a processing combination of high power and high scanning speed (320 W, 1 600 mm/s).