Diffusion Studies in Multicomponent Systems

The MSE diffusion research program in multicomponent systems includes experimental studies of intrinsic diffusion and interdiffusion in metallic alloys and intermetallic phases. Investigations have considered diffusion structure and diffusion paths in multiphase systems for interface stability and microstructural evolution, as well as the analysis and development of zero-flux planes and flux reversals for kinetic and thermodynamic interactions among the diffusing species. Such studies have been carried out in several Cu-base, Ni-base and Fe-base ternary alloys, as well as in Ni-base high temperature alloy systems and MCrAlY coatings.

Recent studies include investigations of multiphase diffusion, fuel/cladding compatibility issues, and lanthanide diffusion in U-Pu-Zr fuels in contact with stainless steel claddings, as part of the Integral Reactor Program of Argonne National Laboratory. Current diffusion studies involve MoSi₂ and MoSi₂-Si₃N₄ composites with varying alloying additions, such as W, Re and Al for the assessment of stability of structures as well as of energies of activation for diffusion of the individual components.

Problems of thermo-transport under a temperature gradient are also being examined in binary and ternary systems with special emphasis on U-Pu-Zr alloys and ternary silicides of U and Al.