Properties of Mg-based metal matrix nanocomposites processed by high shear dispersion technique (HSDT) - a review

: Metal Matrix Nanocomposites (MMNCs) often show excellent properties compared to their non-reinforced alloys due to either the achieved grain refinement or Orowan strengthening. Especially in light metals such as aluminium and magnesium as the matrix has the potential to be significantly improved in relation to mechanical properties. Functionalisation can also be achieved in some cases. However, the challenge lies in the homogeneous distribution of the ceramic nanoparticles in the melt, if MMNCs are processed via melt metallurgical processes. The large surface area of the nanoparticles generates large van der Waals forces which have to be overcome. Furthermore, the wettability of the particles with molten metal is difficult. Additional forces can be applied by ultrasound, electromagnetic stirring or even high-shearing. In this paper properties of MMNCs with a light metal matrix will be presented, which were produced with the High-Shearing Dispersion Technique. First, the process with its different characteristics and the underlying theory is presented and then property improvements are discussed by comparing MMNCs to their matrix materials.