Mechanical properties of gradient structured copper obtained by ultrasonic surface rolling

In this study, the gradient structure of copper was obtained by ultrasonic surface rolling process, and its effect on the mechanical properties of copper was systematically investigated. The obtained gradient structure comprises a nanocrystalline layer (NL, 60-130 mu m in thickness) of equiaxed grains, deformed layer (DL, 40-180 mu m in thickness) of deformed grains and center layer (CL) of equiaxed grains. From CL to NL, the grain size decreases from 50 to 0.1 mu m. The yield strength of the samples with gradient structure increases by 76% (from 125.53 to 225.32 MPa) and tensile strength increases by 16% (from 240.40 to 257.24 MPa), owing to the combined strengthening effect of fine grains, dislocations, and textures of gradient structure. This study helps to guide the design and optimization of the copper microstructure to improve the comprehensive mechanical properties.

Automated summary

In this study, the gradient structure of copper obtained by ultrasonic surface rolling process was investigated for its effect on the mechanical properties. The results showed that the samples with gradient structure exhibited significantly improved yield strength and tensile strength, which can be attributed to the combined strengthening effect of fine grains, dislocations, and textures of the gradient structure.