Structural evolution and stability of mechanically alloyed Fe-Ni nanocrystalline

Abstract

The structural evolution and stability of Fe_100−xNi_x (x=10, 20, 35, 50) alloys prepared by mechanical alloying were investigated through X-ray diffraction analysis and transmission electron microscopy. The intrinsic conditions of preparation determining phase stability in nanocrystalline were clarified. After being milled for 120 h, the powders of Fe₉₀Ni₁₀ and Fe₈₀Ni₂₀ consist of a single α(bcc) phase, Fe₃₀Ni₃₀ powders are a single γ(fcc), and for Fe₆₅Ni₃₅ powders there is co-existence of α and γ phases. The as-milled Fe₈₀Ni₂₀ powders annealed at 680 °C exhibits the stability of high-temperature γ phase at room temperature, which is consistent with the theoretical prediction.

Keywords

mechanical alloying / Fe-Ni nanocrystalline / structural evolution / phase stability / martensitic transformation