Dresden 2014 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 25: Topical Session: Thermodynamics at the nano scale II - Thermodynamics

MM 25.3: Vortrag

Dienstag, 1. April 2014, 12:30–12:45, BAR 205

Concept of multicomponent alloying based on self-organization on the nanoscale. — •Igor A. Abrikosov — IFM, Linköping University, Sweden

We propose a design route for the next generation of nitride alloys via a concept of multicomponent alloying based on self-organization on the nanoscale via a formation of metastable intermediate products during the spinodal decomposition. Experimentally the formation of detrimental wurtzite AlN phase has been identified as a major factor limiting the thermal stability of the state-of-the-art (TiAl)N alloys used in modern hard coating applications. We carry out systematic first-principles calculations aimed at finding potential new multicomponent transition-metal aluminum nitride alloys, and identify Cr as one of the most promising alloying elements. We predict theoretically and demonstrate experimentally that quasi-ternary (TiCrAl)N alloys decompose spinodally into (TiCr)N and (CrAl)N-rich nanometer sized regions. The spinodal decomposition results in age hardening, while the presence of Cr within the AlN phase delays the formation of a detrimental wurtzite phase leading to a substantial improvement of thermal stability compared to the quasi-binary (TiAl)N or (CrAl)N alloys [1].

[1] H. Lind, R. Forsen, B. Alling, N. Ghafoor, F. Tasnadi, M. P. Johansson, I. A. Abrikosov, and M. Oden, Appl. Phys. Lett. 99, 091903 (2011); H Lind, F Tasnadi and I A Abrikosov, New J. Phys. 15 095010 (2013)