About 14% of the global greenhouse emissions originate from the transportation sector, and this number increases to approximately 30% in regions such as Europe or the United States. Although CO2 emissions are overall decreasing in the EU, due mostly to the decarbonization of industry, the EU emissions from transport have experienced an increase in the past few years. Urgent measures must therefore be taken in order to foster transport sustainability.

 Magnesium alloys, with a density that is approximately 30% lower than that of aluminum alloys, are envisioned as key materials for vehicle lightweighting. Despite their excellent properties, including high recyclability, their widespread use is however challenged, among others, by the comparatively better specific behavior of polymer-based composites. Significant efforts are thus timely in order to improve the strength of these promising alloys.

 Precipitation constitutes a microstructural design tool that has been utilized successfully to strengthen many metals such as, for example, aluminum alloys and nickel superalloys. However, particle hardening has proven significantly less effective in magnesium, thus severely limiting the possibilities for structural alloy design. Exploiting the hardening potential of precipitates in magnesium alloys requires a profound understanding of the interaction between dislocations and precipitates. The relative contribution of each mechanism depends on testing conditions, composition, microstructure and texture.

 This lecture will review recent research on dislocation-particle interactions in magnesium alloys using a combined approach including micromechanical testing, slip trace analysis, and high resolution transmission electron microscopy. The interaction of basal and non basal dislocations with particles of different sizes and orientations with respect to the matrix will be discussed. Guidelines for the design of stronger magnesium alloys will be proposed on the light of the above findings.