Open Access

ARTICLE

The Influence of the Grain Size Effect on the Mechanical Properties of Metallic Tungsten during Nanoindentation

Duo Li¹, Shuhao Kang¹, Yukun Liu², Yang Shen², Ruihan Li³, Yuhu Liu¹, Shujun Huang⁴, Xin Wu⁵, Huan Liu^2,*

1 Institute of Intelligent Manufacturing and Information Engineering, Shanghai Jiao Tong University, Shanghai, China
2 Center of Ultra-Precision Optoelectronic Instrumentation Engineering, Harbin Institute of Technology, Harbin, China
3 College of Mechanical and Electrical Engineering, Harbin Engineering University, Harbin, China
4 School of Urban Railway Transportation, Shanghai University of Engineering Science, Shanghai, China
5 School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai, China

* Corresponding Author: Huan Liu. Email:

(This article belongs to the Special Issue: Mechanical Behavior of Materials with Advanced Modeling and Characterization)

Computers, Materials & Continua 2026, 88(1), 17 https://doi.org/10.32604/cmc.2026.078734

Received 06 January 2026; Accepted 08 April 2026; Issue published 08 May 2026

Abstract

Tungsten plays a critical role in semiconductor electrical interconnects, and a thorough understanding of its mechanical properties is essential for optimizing its processing and performance. However, few studies have explored the effect of grain refinement on the mechanical behavior of tungsten. The work indicates a phenomenological transition around ~7.3 nm within the tested grain-size range that governs the nanoindentation response of tungsten. To establish this, we performed molecular dynamics (MD) simulations of nanoindentation for different grain sizes and analyzed surface pile-up, elastic recovery, atomic displacement, loading force, hardness, stress/strain behavior, dislocation density, and dislocation evolution. When the average grain size is smaller than ~7.3 nm, an increase in grain size leads to a higher elastic recovery ratio in the depth direction, increased loading force and hardness, and elevated local von Mises stress near the indenter, accompanied by greater shear strain. However, the number of surface pile-up atoms and the associated pile-up area decrease. The distribution and magnitude of dislocation density are strongly influenced by grain size. These findings demonstrate that grain refinement can effectively improve the mechanical performance of tungsten, offering further insights for the nanoscale processing of this material.

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