Preparation of Fe-TiN Nanocomposite-powders and their Shock Consolidation

Abstract

Fe₁₀₀-xTix (X= 25, 50, 75 at.%) powder mixtures were milled in vibrational ball mill under N₂ atmosphere, and the milled powders were dynamically compacted by using a propellant gun. It was found that Fe-Ti milled powders were consisted of α-iron and TiN phases. These powders had nanostructures with grain sizes of about 4-7 nm in diameter. By dynamically compacting the Fe₅₀(TiN)₅₀ powder at the shock pressures of 38.6 GPa and above, a nanocomposite material having an extremely high hardness (Hv-1300) was obtained. When the material was annealed at 1073 K for 5 h, the grain growth occurred to about 20 nm for α-iron phase, and the hardness was increased to a maximum value (Hv-1600). With increasing annealing temperature above 1173 K, the grain growth occurred and the hardness drastically decreased.