Position-dependent nanoindentation edge effect in single crystal tungsten via molecular dynamics simulations

Single crystal tungsten, a high-temperature refractory metal with exceptional properties, is widely used in aerospace, military, and nuclear fusion applications. Understanding its nanoscale mechanical behavior is crucial for advanced material design and extreme environment applications. This study employs molecular dynamics simulations to investigate the nanoindentation behavior of single crystal tungsten, with a focus on the edge effect. The results reveal that surface atomic stacking exhibits a non-monotonic trend as the indentation position shifts from the center to the edge, while the number of side extruded atoms increases monotonically near the edge. The edge region demonstrates reduced resistance to deformation, lower hardness, and pronounced plastic flow. Stress and temperature distributions further confirm that edge constraints lead to localized stress concentration and thermal gradients. These findings provide critical insights into the nanoscale mechanical behavior of tungsten, aiding in the optimization of high-performance materials for extreme conditions.