  Magnesium (Mg) has the lowest density of all structural metals and has
excellent potential for wide use in structural applications. While pure Mg has
inferior mechanical properties; the addition of further elements at various
concentrations has produced alloys with enhanced mechanical performance and
corrosion resistance. An important consequence of adding such elements is that
the saturated Mg matrix can locally decompose to form solute clusters and
intermetallic particles, often referred to as precipitates. Controlling the
shape, number density, volume fraction, and spatial distribution of solute
clusters and precipitates significantly impacts the alloy's plastic response.
Conversely, plastic deformation during thermomechanical processing can
dramatically impact solute clustering and precipitation. In this paper, we
first discuss how solute atoms, solute clusters, and precipitates can improve
the mechanical properties of Mg alloys. We do so by primarily comparing three
alloy systems: Mg-Al, Mg-Zn, and Mg-Y-based alloys. In the second part, we
provide strategies for optimizing such microstructures by controlling
nucleation and growth of solute clusters and precipitates during
thermomechanical processing. In the third part, we briefly highlight how one
can enable inverse design of Mg alloys by a more robust Integrated
Computational Materials Design (ICMD) approach.
