Build quality evaluation of a series of lattice structures of AlSi10Mg using X-ray tomography

Abstract

Additive manufacturing is a manufacturing technology that has grown from prototyping applications to the production of end-use parts in various industries. It is today possible to produce complex-shaped parts such as cellular or lattice structures in various popular metal alloys relevant to engineering applications. These intentionally designed porous metamaterials allow unique properties that have applications in next-generation aerospace components and medical implants, amongst others. The wide adoption of lattice structures has been in part held back by quality concerns in the manufactured material, including porosity, surface roughness, microcracks, residual stress and microstructural nuances. These issues are generic to all AM materials, but at the scale of lattice structures they have a stronger influence on mechanical and other performance; and are more critical to the successful manufacturing and final application. While lattices have widely studied in the last few years, few comparisons of build quality exist for different designs or architectures. In this work, using the laser powder bed fusion process with AlSi10Mg alloy, we report an extensive and detailed characterization of the build quality of a range of different cellular architectures, utilizing X-ray computed tomography (CT). Some key conclusions are made that can be used to inform future designs, enhancing build success and design confidence. Some recommendations are made regarding the use of CT for lattice structure characterization.