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 epsilon-Cu phase.