A compact coherent nanoprecipitate architecture for enhanced strength in a Ni-rich medium-entropy alloy

We engineer a unique compact coherent architecture in a Ni-rich MEA, featuring cuboidal L1₂-γ′ nanoprecipitates fully encapsulated by a continuous D0₂₂-γ″ shell. This structure elevates the yield strength to 1122 MPa from 951 MPa (for the alloy containing monolithic γ′ precipitates) and retains a uniform elongation of 14.9%. The synergy originates from a dual mechanism where the coherent D0₂₂-γ″ shell strongly impedes dislocation motion, and the composite precipitate subsequently undergoes coordinated shear via a complex stacking fault sequence, effectively accommodating strain without severe localization. This work establishes architectural control of coherent precipitates as an effective design principle for performance optimization.