Method to produce two-phase nanocomposites in solid state

We demonstrate that full-density, bulk, two-phase nanocomposites can be produced starting from a powder mixture of two coarse-grained individual phases in equilibrium. Instead of going through liquid or vapor phase precursors, mixing is achieved through mechanical milling, a highly nonequilibrium driven process imposing external forcing. The precursor created is a supersaturated solid solution with nanocrystalline grain sizes. Upon subsequent hot consolidation to bulk samples, phase separation occurs on the scale of the nanograins, forming two-phase nanocomposites in situ. Transmission electron microscopy of the Cu₆₀Fe₄₀ sample presented in this paper confirm that, after full density processing using the sinter forging consolidation scheme, nanophase grains are maintained and a homogeneous two-phase microstructure is obtained.