RADIATION-INDUCED SEGREGATION IN NI-ALLOYS BY DEUTERIUM ION IRRADIATIONS

The foils of binary alloys of Ni-9.0 at%Si, -5.0 at%Co and -4.9 at%Cu solid solutions were irradiated with 3.2 x 10(-15) J (20 keV) deuterium ions. In order to study the effect of D atoms on radiation-induced segregation (RIS) in Ni binary alloys under D+ irradiations, RIS by the D+ irradiation was compared with that by 3.2 x 10(-13) J (2 MeV) electron irradiation. The solute concentration around grain boundaries in the irradiated specimens was measured by EDS in an electron microscope. By the D+ irradiations at 573 K undersized Si atoms are more enriched, slightly oversized Co atoms are little depleted and oversized Cu atoms are more depleted at grain boundaries in comparison with the solute segregation of the electron irradiations. No enhancement of solute segregation by the D+ irradiation is observed at 773 K. The increase of Si segregation and Cu inverse segregation due to the D+ irradiation was discussed from the interaction of gas atoms with vacancies. It is suggested that Cu atoms of the Ni-Cu alloys are transported not only by free vacancies but also by vacancies trapped with deuterium atoms in D+ irradiation.