Dresden 2011 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 46: Mechanical Properties III

MM 46.7: Talk

Friday, March 18, 2011, 12:00–12:15, IFW D

Investigation of the mechanical properties of the 413-MAX phase Ti₄AlN₃ by perturbed γ-γ angular correlation — •Christoph Brüsewitz¹, Daniel Jürgens¹, Michael Uhrmacher¹, Hans Hofsäss¹, and Michel W. Barsoum² — ¹II. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen, Germany — ²Dep. Mat. Sci. & Eng., Drexel University, Philadelphia, PA 19104, USA

MAX phases are nanolaminated layered carbides and nitrides, which feature an unusual set of the best attributes of both metals and high-performance ceramics. Due to their layered structure these phases are good electric and thermal conductors, superb thermal and mechanical shock resistant and easily machinable. To investigate the microscopic behaviour of these phases under uniaxial load, we selected Ti₄AlN₃ and performed measurements by using perturbed γ-γ angular correlation (PAC). The PAC method uses the oscillating anisotropy in the decay cascade of implanted ¹¹¹In, which is influenced via the hyperfine interaction by the local probe environment. The measured electric field gradient (EFG) and especially the change of the frequency damping show the elasticity under applied and after released pressure in a sub-nanometer around the Al-site. Those measurements were not affected by the already known kink band formation in MAX phases under applied stresses, which are used to describe the high elasticity on the µm scale, as long as the phase is still stable. Therefore XRD was chosen to prove that the phase did not decompose. This work is supported by the DFG under contract HO 1125/19-1.