Effect of Scan Strategy on Mechanical Properties of AlSi12 Lattice Fabricated by Selective Laser Melting

Abstract

In this study, the influence of scan strategies, such as scan order and scan patterns, on compressive load capacity was investigated for the aluminum alloy AlSi12-made lattice structures fabricated by selective laser melting. The scan order of concentric scan patterns affected compressive load capacity. Better mechanical properties were obtained when the scan order was set from the outside. Setting the scan order from the inside caused coarsening of the grains at the center of the strut, thus worsening the mechanical properties due to the reduced area fraction of the finegrained regions. The mechanism of such grain coarsening was explained based on the heat transfer direction. Furthermore, the scan pattern also affected the size and orientation of the grains in the lower zone of the strut as well as its geometrical accuracy. A stripe pattern with a rotation of 67° from layer to layer decreased the geometrical accuracy but increased the hardness of the strut owing to the smaller size and random orientation of the grains in the lower strut zone.