Anisotropy and symmetry in the elastoplastic deformation of single crystals under scratching: Unravelling the microscopic deformation mechanisms

Z. Zhang, Y.J. Lee, Q. Yan, H. Wang, Z. Tong, X. Jiang
Tribology International 202 (2025) 110341

Abstract. The nanoscratch test, as an established technique for assessing material tribological properties has received significant attention. However, the symmetry and anisotropy in scratching performances as well as the quantitative correlation between the orientation-dependent deformation and inherent microscopic deformation mechanism remain unexplored. Herein, crystal plasticity simulations can quantitatively capture scratching forces, elastic recovery, and surface pile-ups, as well as accurately describe inner deformation fields and lattice rotation patterns, as confirmed by experimental results. The simulation results reveal that surface pile-up and elastic recovery mappings on (001)-, (011)-, and (111)-oriented samples exhibit eight-fold, four-fold, and six-fold symmetries, respectively. The orientation-dependent location and intension of both slip activities and lattice rotation, determine the features of macroscopic elastoplastic deformation under scratching.

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Supported by Ministry of Education, Singapore, Academic Research Funds (Grant Nos.: A-8001225–00-00 and MOET2EP50220–0010).