Anelasticity of Fe-based Ordered Solid Solutions and Intermetallics Compounds

• Applicant: Professor Dr. Hans-Rainer Sinning
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2004 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5424594

Different mechanical spectroscopy techniques will be combined to study systematically, over wide ranges of frequency, temperature, and amplitudes, the spectra of intemal friction and anelastic relaxation in short and long range D03 and B2 ordered alloys (Fe-Al, Fe-Si, Fe-Co, Fe-Cr, including the intermetallic compounds Fe3Al, FeAl, Fe3Si, and FeCo), and mixed multi-component compositions with different degree of order (e.g.: Fe-(Al+Cr), Fe-(Si+Al)). The goals are twofold: (1) On the fundamental side, the mechanisms of anelasticity are to be clarified in terms of interstitial, vacancy and dislocation substructures. This includes new information about the distribution of interstitial around substitutional atoms with short range ordering, mobility of vacancies and kink pairs on dislocations, and interaction between interstitial atoms and vacancies. (2) Under the viewpoint of the application, such specific mechanical spectroscopy results are used to study commercially important phenomena, like yield stress anomalies of Fe3Al and Fe3Si-based intermetallics (dislocation mobility and pinning mechanisms), various types of brittleness, and high damping capacity of Fe-Al, Fe-Cr and Fe-Co based alloys (vibration and noise reduction).

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Hartmut Neuhäuser