Self-Organization of Dilute Copper Binary Alloys Under Ion Irradiations

The phase stability of materials under irradiation has been a subject of renewed interest in recent years due to the increased demands that next generation nuclear power sources will place on the performance of materials. The challenge in understanding materials under irradiation is that they are driven far from equilibrium by the continual creation of point defects and the random ballistic mixing of alloy components. As a consequence, the microstructural evolution of irradiated alloys is controlled by complex kinetic processes. The work presented here examines the effect that 1.8 MeV Kr+ ion irradiation have on model alloy systems, dilute Cu-Ag, Cu-Nb, Cu-Mo and Cu-Fe alloys, and compares their behaviors with existing models on driven systems. For the first three alloys, the microstructure is characterized using X-ray diffraction, transmission electron microscopy and Rutherford backscattering. For Cu-Fe alloys, the microstructure is studied using a combination of magnetization measurements and atom probe field ion microscopy. The results show that the microstructural behaviors of these alloys, with the exception of Cu-Mo, are in good qualitative agreement with the model, showing compositional patterning over a range of irradiation temperatures. For Cu-Ag, Cu-Nb and Cu-Fe, the boundaries separating patterning and macroscopic coarsening are dependent on solute diffusivity and solute solubility. In Cu-Mo, the high level of immiscibility between the two elements leads to the formation of a nanocomposite that is kinetically stable under both temperature and irradiation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science and Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Chee, See Wee

Contributors dc:contributor

• Averback, Robert S.

• Engineering, Nuclear

Language dc:language

eng

Identifier

(MiAaPQ)AAI3337723

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/82826