GRAIN-BOUNDARY SEGREGATION UNDER NEUTRON-IRRADIATION IN DILUTE ALLOYS

Irradiation-induced segregation mechanisms are classified into solute- point-defect complex type and inverse Kirkendall type. For solutes tha t have a strong interaction with interstitials in a dilute alloy, the complex effect plays an important part in the segregation. Our earlier model describing solute grain boundary segregation during neutron irr adiation in dilute binary alloys, based on the complex effect mechanis m, is modified by considering the irradiation-enhanced solute diffusio n and the long-range recombination effect of freely migrating point-de fects, and expanded to evaluate solute segregation in dilute ternary a lloys through consideration oi. solute-solute competition for segregat ion sites. Applications of the model to predictions of P grain boundar y segregation in neutron irradiated alpha-Fe and Fe-B-P and Fe-C-P all oys indicate that the model has reasonable validity. (C) 1998 Elsevier Science B.V. All rights reserved.