Fachbereich 11 - Physik
Institut für Materialphysik
Diffusion and Segregation in Grain and Interphase Boundaries

Interface diffusion in intermetallics

Mechanical properties such as yield strength and creep resistance strongly depend on the microstructure and in turn on the atomic mobility in grain and interphase boundaries, especially if functional high temperature materials are considered, e. g. intermetallic compounds in the systems Al-Ti and Al-Ni. The technologically applied titanium aluminides for instance consist of two-phase a₂-Ti3Al/g-TiAl alloys, predominantly with lamellar microstructure. We have therefore investigated Ti self-diffusion in grain- and interphase boundaries of Ti3Al and TiAl and a₂-Ti3Al/g-TiAl, respectively, as well as Ni grain boundary diffusion in NiAl in dependence of temperature and composition. The systematics between bulk and interface boundary diffusion is evaluated. Reasonable interpretation of grain- and interphase boundary diffusion and the atomistic structure of a₂/g phase boundaries was elaborated.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft

Beteiligte Wissenschaftler:

Dr. A. Bartels (Technische Universität Hamburg-Harburg), Dr. S. V. Divinski, Prof. Dr. Chr. Herzig (Leiter), Dr. F. Hisker, Dr. T. Przeorski

Veröffentlichungen:

Herzig, Chr., S. V. Divinski, St. Frank, T. Przeorski: Bulk and grain boundary diffusion in intermetallic compounds of the systems Ni-Al and Ti-Al Defect and Diffusion Forum, 194 - 199, 317 (2001)

Herzig, Chr., T. Wilger, T. Przeorski, F. Hisker, S. V. Divinski: Titanium tracer diffusion in grain boundaries of a-Ti, a₂-Ti3Al, and g-TiAl and in a₂/g interphase boundaries, Intermetallics, 9, 431 (2001)

Divinski, S. V., F. Hisker, A. Bartels, Chr. Herzig Interphase boundary diffusion of 44_Ti in two-phase TiAl with lamellar a₂/g structure Scripta, Mater., 45, 161 (2001)