Influence of initial lattice misorientation on the global and local response during wedge nanoindentation of single-crystal tungsten

Materials Science and Engineering A, vol. 978, pp. 151088

Abstract

This work investigates the effect of small initial lattice misorientations on wedge nanoindentation in body-centered-cubic single-crystal tungsten using crystal plasticity finite element modeling. The study focuses on the sensitivity of both global and local indentation responses to controlled rotations of the initial crystal frame about the specimen axes. In the model, the imposed perturbation represents a crystallographic offset at the onset of indentation, while the specimen geometry, contact conditions, and boundary conditions remain unchanged. The simulations show that small initial lattice misorientations produce only minor changes in the global load–displacement response, but substantially modify the local deformation field beneath the wedge. In particular, the lattice-rotation field becomes increasingly asymmetric, and the spatial distribution of dominant slip activity changes depending on both the axis and the magnitude of the imposed misorientation. Rotations involving the loading-axis component generate the strongest asymmetry, whereas in-plane rotations primarily influence the sign and localization of the lattice-rotation pattern beneath the indenter. Consistent with this behavior, the asymmetry index increased from a residual value of approximately 0.012 in the aligned reference configuration to substantially larger values for misoriented crystals, despite only minor changes in the corresponding load–displacement response. These results indicate that local observables, such as lattice rotation and slip activity, are significantly more sensitive to the initial crystallographic state than the global indentation curve alone. The study therefore provides a mechanics-based framework for interpreting wedge-indentation experiments and associated orientation-mapping measurements in anisotropic crystalline materials, with particular relevance to single-crystal tungsten.

Authors 5

1. T.O. Fenercioğlu

   Forschungszentrum Jülich

   Affiliation as printed

   Institute for Advanced Simulations – Materials Data Science and Informatics (IAS-9), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany

   Institute of Energy Materials and Devices - Microstructure and Properties of Materials (IMD-1), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany

2. Michael Budnitzki corresponding

   Forschungszentrum Jülich

   Affiliation as printed

   Institute for Advanced Simulations – Materials Data Science and Informatics (IAS-9), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany

3. Jin Wang

   Forschungszentrum Jülich

   Affiliation as printed

   Institute of Energy Materials and Devices - Microstructure and Properties of Materials (IMD-1), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany

4. S. Sandfeld Aachen Chair of Materials Data Science and Materials Informatics Faculty 5 – Georesources and Materials Engineering

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

   Chair of Materials Data Science and Materials Informatics, Faculty 5 – Georesources and Materials Engineering, RWTH Aachen University, Aachen, 52056, Germany

   Institute for Advanced Simulations – Materials Data Science and Informatics (IAS-9), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany

5. R. Schwaiger Aachen Chair of Energy Engineering Materials Faculty 5 – Georesources and Materials Engineering

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

   Chair of Energy Engineering Materials, Faculty 5 – Georesources and Materials Engineering, RWTH Aachen University, Aachen, 52056, Germany

   Institute of Energy Materials and Devices - Microstructure and Properties of Materials (IMD-1), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany