3D Atom Probe Analysis on Nb and Mo Segregation during Recrystallisation of α-Fe
Atomic-scale interface segregation behaviour of Nb and Mo during different stages of recrystallisation of a-Fe has been investigated using a three-dimensional atom probe (3DAP). Experimental procedures to analyse a specific region of interest in the specimens and to determine an orientation relationship between analysed contiguous grains are briefly described, and then analytical artefacts which may affect the measured solute distribution are discussed. Atom probe analysis reveals that Gibbs free energy of segregation of Nb is larger than that of Mo in a-Fe, implying that a stronger solute Nb-interface interaction can be a reason for the larger retardation effect of recrystallisation by Nb addition. The comparison of measured solute profiles at migrating recrystallisation interfaces with calculated solute profiles show that Cahn’s solute drag model gives a reasonable fit to solute profiles for migrating interfaces.
B. Bacroix, J.H. Driver, R. Le Gall, Cl. Maurice, R. Penelle, H. Réglé and L. Tabourot
N. Maruyama and G. D.W. Smith, "3D Atom Probe Analysis on Nb and Mo Segregation during Recrystallisation of α-Fe", Materials Science Forum, Vols. 467-470, pp. 949-956, 2004