This award is under the International Postdoctoral Fellows Program, which enables U.S. scientists and engineers to conduct three to twelve months of research at foreign centers of proven excellence. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twelve-month postdoctoral research visit by Dr. Ralph P. Mason to work with Professor Dr. Eduard Arzt at the Max Planck Institute for Metals Research in Stuttgart, Germany. They propose to develop a model of the creep deformation of dispersion-strengthened intermetallic alloys where the rate of creep deformation is controlled by thermally activated detachment of superlattice dislocations from dispersoid particles. This model will incorporate two attractive interactions between dispersoid particles and superlattice dislocations which lead to the attachment of superlattice dislocations to particles. These attractive interactions which inhibit dislocation motion will be offset by the applied stress and by thermal activation both of which will facilitate dislocation motion. The rate of creep deformation will be determined by the balance of the above elements. The model will be tested against existing data for dispersion-strengthened intermetallics. The proposed research has potential application to the manufacture of high-temperature parts such as blades, vanes and disks in aircraft turbines. The award recommendation provides funds to cover international travel and a stipend for twelve months.
