EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Magnesium alloys exhibit promising properties as bone implant materials due to their biodegradability, non-toxicity and mechanical properties. Compared to steel and Ti, Mg implants can be fully re-absorbed by the human body and the mechanical properties are similar to that of the bones and do not lead to stress shielding. Porous scaffolds are ideal structures for bone regeneration as they allow tissue growth, prevent implant loosening and permit body fluid transportation. However, such structures are difficult to obtain by conventional manufacturing methods, but can obtained by additive manufacturing strategies. Lattice structures of Mg-RE alloys with different strut sizes were manufactured by Laser Powder Bed Fusion (LPBF) process and modified by thermal treatments. The relationship between processing conditions and the microstructure was carefully analysed by means of X-ray µtomography, scanning electron microscopy and electron-backscatter diffraction as well as transmission electron microscopy. The mechanical properties and the fracture mechanisms were ascertained by means of in situ compression tests within an X-ray µtomography system in lattices that have been immersed in simulated body fluid for different time periods. Additionally, in-vitro biocompatibility studies were also conducted. These results were used to ascertain the influence of processing parameters, lattice dimensions and heat treatments on the mechanical and degradation behavior of lattice structures of Mg-RE alloys manufactured by LPBF.