AGING OF AN FE-NI-AL ALLOY IN MAGNETIC-FI ELD

Aging of an Fe-23.3Ni-9.4Al (mass%) alloy was carried out both in the presence of a magnetic field (9 T) and without a magnetic field at 673 , 773, 873 and 973 K for 5 h. The saturation magnetic moment of the sa mples were measured at 200, 100, 50 and 5 K and extrapolated to 0 K. A systematic difference in average magnetic moment is observed between the samples aged with and without magnetic field. Except for aging at 773 K, the average magnetic moment of the samples aged under magnetic field is smaller than those aged without a magnetic field. TEM observa tion showed the evidence of spinodal decomposition of disordered bcc ( A2) and ordered bcc (B2) phases. The difference in magnetic moments is attributed to the difference in kinetics of ordering/decomposition du e to the magnetic field.