Dynamic Precipitation during High‐Pressure Torsion of a Magnesium–Manganese Alloy

An ultrafine‐grained magnesium alloy has been produced through room temperature high‐pressure torsion (HPT) of solutionized Mg–1.35 wt% Mn. Dynamic precipitation of nanometer‐scale Mn particles occurs during deformation. These particles populate the grain boundaries, acting as pinning sites which allow the alloy to develop a grain size of 140 nm after 0.5 rotations. Further, HPT deformation results in a gradual increase in grain size with no increase in precipitate size. Despite the extensive deformation applied, the alloy does not develop a bimodal grain structure and retains a grain size of 230 nm after 10 complete rotations, demonstrating the stability and effectiveness of these pinning particles.