The experimental investigation and modeling on the mechanical behavior of dual-phase approximate equiaxial nanocrystalline AgCu alloy

Nanostructured dual-phase equiaxial alloy (DPEA) possesses the unique mechanical properties of high strength and ductility. However, the characterization of mechanical behavior and its elastic-plastic response of DPEA remain to be solved. In this paper, in-situ consolidation dual-phase approximate equiaxial nanocrystalline (NC) AgCu alloys have been synthesized and relevant tensile and nanoindentation tests have been carried out. Experimental results indicates that dual-phase approximate equiaxial NC AgCu alloys have good strength, ductility and a certain creep resistance. Moreover, a theoretical model based on mechanics has been proposed to simulate the stress-strain relationship, strain hardening rate and creep strain rate of dual-phase equiaxial NC AgCu alloy. The plastic property of regular grain interior (GI) phase and amorphous grain boundary (GB) phase has been addressed by the strain gradient plasticity model. Based on the calculated results of the proposed model is consistent with the experimental results. Our analysis revealed that mechanical properties of DPEA are sensitive to the grain size, content of GI phase, volume fraction of solute cluster and thickness of GB. This research has provided a theoretical framework to design excellent mechanical property of DPEA by optimizing material structure parameters.