Effects of Implanted Solutes and Heavy -Ion Cascades on the Kinetics of Radiation -Induced Segregation in Binary Alloys

Various electron and dual ion irradiations were conducted to investigate the effect of implanted solutes and heavy-ion cascades on the fluxes of freely-migrating defects which drive radiation-induced segregation (RIS) in Ni-9at.%Al and Cu-1at.%Au alloys. To study the effect of solute implantation on RIS, the segregation rate of Al atoms in Ni-9at.%Al following the implantation of Ne, Sc, or Zr was quantified using in-situ measurements of the growth rate of gamma '-Ni3Al precipitate zones produced during 900-keV electron irradiations between 450 and 625°C in a HVEM. It was found that the implantation of 0.06at.%Ne, 0.12at.%Sc, and 0.06at.%Zr resulted in very strong, small, and no RIS suppression in Ni-9at.%Al, respectively. The Ne effect increased with increasing implantation dose at 450°C and with increasing electron irradiation temperature between 550 and 625°C. In-situ Rutherford backscattering (RBS) was used to measure the RIS suppression effect of heavy-ion bombardment, i.e., 300-keV Al+, 800-keV Cu+, and 1.2-MeV Ag+, on 1.5-MeV He+-induced Au transport away from the near-surface region during concurrent He + and heavy-ion irradiation of Cu-1at.%Au at 400°C. Results demonstrated that the suppression of He+-induced RIS in Cu-1at.%Au caused by concurrent heavy-ion irradiation correlated well with the cascade volume produced by Al+, Cu+, or Ag+ per second and was independent of the heavy ion used. Computer simulations of dual beam experiments based on the Johnson-Lam model for RIS kinetics in binary alloys were also performed, and these simulations supported the RBS results.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Nuclear Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Giacobbe, Michael John, III

Contributors dc:contributor

• Jaems F. Stubbins

• Engineering, Materials Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI9944860

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85945