Extended Data Fig. 2: Dislocation multiplication in two microstructures during tensile deformation measured by the synchrotron-based high-energy X-ray diffraction in situ tensile testing.

(a) Results in M₄ as shown in Fig. 1a with yield strength of 2 GPa as shown in Fig. 2a. a1: The σ_e−ε_e curve by in-situ testing. Arrow: the end of LB propagation. a2: Change of diffraction intensities with tensile strains. a3: Evolution of normalized full width at half maximum (FWHM) for (111), (200), and (220) peaks in fcc lattices as a function of tensile strain. (b) Corresponding results in M₇ with yield strength of 1.6 GPa as shown in Extended Data Fig. 1a. b1: The σ_e−ε_e curve by in-situ testing. Arrow: the end of LB propagation. b2: Change of diffraction intensities with tensile strains. b3: Change of dislocation density (ρ) during tensile deformation. Note that ρ increases from the initial 1.9 × 10¹³ m⁻² to 4.1 × 10¹⁴ m⁻² at first when the LB arrives, then to 4.3 × 10¹⁴ m⁻² by the end of LB propagation, and finally to 2.2 × 10¹⁵ m⁻² after uniform deformation (Fig. 3e). The share of the increment in ρ during the LB propagation is 17% of total increment. Note the mass formation of dislocations during uniform deformation, in sharp contrast to what happened in M₄ (Fig. 3e).