Fig. 3

Microstructural characterization of post-deformed NC-Cu-10 at.% Ta tested at multiple strain rates and temperatures. Post-deformed BF-STEM micrograph of NC-Cu-10 at.% Ta at a 298 K and 10⁻² s⁻¹, b at 873 K and 10⁻² s⁻¹, c at 298 K and 4 × 10³ s⁻¹, d at 873 K and 4 × 10³ s⁻¹, e Taylor anvil tested sample, and f magnified view of the micrograph in e showing twins inside a Cu grain. At lower temperatures (298 K), the high stress contributes toward the nucleation of partial dislocations. At higher temperatures (873 K), emission of dislocations is favored even at 4 × 10³ s⁻¹ strain rate. The white bars in a–d and f indicate a length scale of 50 nm and that in e indicates a length scale of 100 nm