Mechanical properties of AlSi10Mg lattice structures fabricated by selective laser melting

Abstract

Al alloy porous structures have potential application in industries such as light aerospace and some heat exchanger products. A particular advantage of selective laser melting (SLM) over conventional manufacturing processes is its ability to fabricate periodic lattice structures with controllable volume fractions. In this paper, 12 samples of AlSi10Mg periodic diamond lattice structures with interconnected high porosity and volume fractions from 4.5% to 22.5% were fabricated by selective laser melting. At the same time, the optimized radius at the node is introduced to reduce stress concentration. The as-built AlSi10Mg lattice was well formed without large appeared voids and cracks. A full-scale three-dimensional finite element (FE) model was established to evaluate the macroscopic deformation of the lattice structures and the microscopic stress and strain evolution in the solid struts. Local plastic stresses were found to generate near the nodes, thus forming plastic hinges, while most of the struts remain elastic. Evolution under compressive loads determines the mechanical properties of the diamond lattice structures and failure mechanism.