Growth Kinetics of β´Precipitation in a Ferritic Matrix During Isothermal Aging of Cu-containing Fe-10at.%Ni-15at.%Al alloys

A precipitation study was carried out during the isothermal aging at 850 °C for Fe-10at.%Ni-15at.%Al, Fe-10at.%Ni-15at.%Al-2.5at.%Cu and Fe-10at.%Ni-15at.%Al-5at.%Cu alloys. The experimental, Calphad, Kinetic/Precipitation calculated results indicated that Cu-addition to ternary alloy promoted a higher volume fraction of β´precipitates, which caused better response Cu-containing coarsening resistance highest 2.5 at. % alloy, compared because its lower interfacial free energy, 0.009 Jm-2, between precipitate matrix. Cu alloying element located mainly in β´ according expected thermodynamic behavior, it an atomic relation Ni Al close NiAl intermetallic compound β´phase. content 5 0.04 thus fastest process.