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Modeling the Creep Behavior of Lamellar NiAl-(Cr,Mo) Composites Using Three-Scale Homogenization

Claudius Klein1*, Jan Vollhüter2, Steffen Neumeier2, Alexander Kauffmann3, Thomas Böhlke1

1 Karlsruhe Institute of Technology (KIT); 2 Friedrich-Alexander-Universität Erlangen-Nürnberg; 3 Ruhr University Bochum

Homogenization, Micromechanics & Multiscale Identification · C223
Thursday, 3 September 2026, 12:25–12:50 · Chair: Matti Schneider

Keywords: crystal plasticity, homogenization, high temperature, creep

The macroscopic mechanical response of composite materials depends on the properties of the constituents as well as the microstructure, i.e., the spatial arrangement of the constituents. In this talk we focus on the high temperature creep response of a eutectic NiAl-(Cr,Mo) composite [1], which forms domains (eutectic colonies) within which two metallic phases are arranged as ultrafine lamellar structures. Mesoscopic creep experiments of individual colonies showed that the minimum creep rate spans several orders of magnitude depending on the load direction relative to the lamination direction. The apparent Norton exponent also shows a strong anisotropy. Both effects are due to an inhomogeneous stress partitioning between the two phases which originates from the lamellar morphology and the high material contrast. In order to model the macroscopic mechanical response of the material system, we make use of a three-scale homogenization scheme involving two length scale bridges. For this, we describe the lamellar microstructure as a periodic rank-1 laminate [2], which allows for an efficient evaluation of the effective behavior of a single colony. To account for the interaction between different colonies, we use numerical homogenization techniques, e.g., the description of the mesostructure as a Laguerre tessellation [3] with prescribed interface orientation distribution [4] and its discretization using finite elements. After identification of the constitutive laws of the single phases, we investigate the influence of different interface orientation distributions on the macroscopic creep response.

References

  1. K. Titz, J. Vollhüter, P. Randelzhofer, S. Neumeier, M. Göken, B. Wahlmann, and C. Körner, Design and characterization of a novel NiAl–(Cr, Mo) eutectic alloy, Advanced Engineering Materials, 26(9):2302079, 2024.
  2. G. W. Milton, The theory of composites, 1995.
  3. J. Kuhn, M. Schneider, P. Sonnweber-Ribic, and T. Böhlke, Fast methods for computing centroidal laguerre tessellations for prescribed volume fractions with applications to microstructure generation of polycrystalline materials, Computer Methods in Applied Mechanics and Engineering, 369:113175, 2020.
  4. K.-I. Kanatani, Distribution of directional data and fabric tensors, International Journal of Engineering Science, 22(2):149–164, 1984.