Microstructure and compressive properties of Al-Si10-Mg lattice structures manufactured using selective laser melting

摘要

In this study, the aluminum alloy lattice structure was processed using selective laser melting, and the compressive behaviour was studied. When the porous aluminum alloy was compressed along the building direction, the compressive stress initially increased, followed by a decrease, and then another increase. The aluminum alloy lattice structure mainly underwent the stages of elasticity, shearing, collapse, and then densification in the course of the compression process; the fracture primarily occurred at the joints of the pillars and the support plates. Moreover, the fractures of the aluminum alloy lattice structure, as prepared by selective laser melting, exhibited dimples of different sizes and shapes. The silicon content at the bottom of such a dimple was higher than that at the edges. When the stress level reached its limit and was insufficient to coordinate the plastic deformation of the two phases (alpha-aluminum / silicon interface), micro-pores formed at the interface (the dimples resulted from the breakage of numerous micro-pores after aggregation), which caused the silicon content at the bottom of the dimple to be higher than that at the edge.