Fig. 2: Impacts of TGMs on mechanical properties.

a Comparisons of experimental stress-strain responses in the cases with and without TGMs, in which the definitions of A_i and B_i refer to Fig. 1e. b The specimen and dual-scale DIC technique. c Comparisons for the contributions to elongation and strength (yield stress corresponding to 2% plastic strain) between beneficial TGMs in AM SXs (amplitudes of type #3 and #4, as identified by simulations), and typical gradient microstructures in as-cast Ni-based polycrystals, including gradient grain size produced by severe torsion deformation⁵⁷, surface mechanical attrition treatment (SMAT)⁵⁸, shot peening⁵⁹, and laser shock peening (LSP)⁶⁰; gradient residual stress produced by LSP⁶¹; solute segregation/gradient γ channel width produced by shear flow casting⁶².