Scalability of the mechanical properties of selective laser melting produced micro-struts

Selective laser melting (SLM) is a manufacturing process that builds up metallic or ceramic parts layer by layer directly from 3D-computer-aided design data, offering, for example, the advantage of imposing little restrictions in terms of geometric complexity. One of the main challenges of the SLM process is to improve its efficiency by increasing the build rate of the process and thereby decreasing time and cost. One way of achieving this is increasing the applied laser power and beam diameter, thereby melting more volume in a shorter period of time. Another option of improving efficiency is reducing the volume of the material which has to be melted, made possible by the aforementioned limitless geometric freedom offered by the SLM process. Hereby, one can generate hollow parts for better exploitation and adaption of the volume to specific load cases. Large volumes can be replaced by lattice structures with a certain volume fraction, saving weight and production time by maintaining the stiffness of the structure. To ensure the mechanical properties of the new light-weight structures are comparable to the properties of conventional solid base material, several different lattice structures have already been investigated, all consisting of countless little struts. Therefore, here various formats of single- and multistruts have been built to investigate the scalability of the produced material's mechanical properties. This paper presents the results, which will be used for better prediction of mechanical properties of SLM manufactured lattice structures.