Qualification of a magnesium-based in-situ nanocomposite for hot extrusion

The aim of the proposed research project is the qualification of a new nanoparticle-reinforced magnesium material for forming technology. With its low density, magnesium offers great potential in lightweight design but has only limited formability due to its lattice structure. The use of ceramic nanoparticles in a magnesium melt enables an increase in strength and, in some cases, also ductility in the casting through Orowan reinforcement and grain refinement, particularly with the use of aluminum nitride particles. The mechanical properties are significantly influenced by the distribution of the nanoparticles, which is why the method of incorporation is of crucial importance. The aim of this project is to increase the strength and, in particular, the ductility of a magnesium alloy through the in-situ synthesis of aluminum nitride to make it more usable for forming technology. For this purpose, vanadium nitride particles of various sizes are stirred into two different magnesium alloys with ultrasonic assistance during the casting process. The particle size used and the particle distribution achieved are examined and optimized by mechanical and metallographic characterization methods. The new material is then characterized for hot deformation and compared to the initial magnesium alloy in miniaturized extrusion experiments in order to gain a comprehensive understanding of the forming behavior and define a process window. In a further step, these findings are transferred to the extrusion of application-oriented geometries such as hollow and flat profiles to investigate the influence of nanoparticle reinforcements on the anisotropy of the extruded profiles. The forming experiments are continuously supported by numerical simulations, with the help of which the experimentally determined microstructure development can be described depending on the extrusion parameters. In this way, a comprehensive understanding of the possibilities of using nanoparticles to improve the formability of magnesium alloys is gained.