SANS study of phase decomposition in Fe-Cu alloy added by Ni and Mn

Small-angle neutron scattering ( SANS ) measurements were mainly carried out in order to investigate the structure change during early stage of phase decomposition in Fe-Cu-Ni-Mn quaternary alloy.The fact that the nuclear Guinier radius becomes larger than the magnetic one beyond about 2 nm is attributed to the formation of segregated layer enriched by Ni and Mn around fcc copper-rich precipitate.The calculated SANS intensities have been well fitted simultaneously with both experimental data of magnetic and nuclear components.Addition of Ni and Mn in Fe-Cu binary alloy was suggested to promote the precipitation reaction of 6-CU phase.