Strength ceiling smashed for light metals

Nanoscale particles have been uniformly dispersed in a magnesium alloy, yielding composites with record-breaking strengths — and raising the prospect of using magnesium as a lightweight metal for structural applications. See Letter p.539 A new route to magnesium alloy composites The best magnesium alloys currently available are remarkably light but lack the strength offered by other structural metals. Magnesium-based composites could provide a way of retaining lightness while adding strength. Here Xiao-Chun Li and colleagues demonstrate the production of a dense uniform dispersion of silicon carbide nanoparticles (14 per cent by volume) in magnesium via nanoparticle self-stabilization in molten metal. The resulting composite has improved strength, stiffness, plasticity and high-temperature stability. By overcoming the long-standing challenge of dispersing nanoparticles in metal matrices, this new approach may offer a widely applicable route to high-performance light-metal composites.