High strength and plasticity in disordered multilayer graphene reinforced copper composites

Area of Science:

• Materials Science
• Nanotechnology
• Mechanical Engineering

Background:

• Nanocrystalline (nc) metals often exhibit high strength but limited ductility.
• A key challenge in materials science is to enhance both strength and plasticity simultaneously.

Purpose of the Study:

• To design and fabricate ultra-strong yet plastic nc-metal composites.
• To investigate the mechanisms behind enhanced mechanical properties in novel composite materials.

Main Methods:

• Interface nanostructuring using plasma assisted ball milling (PABM).
• Fabrication of disordered multilayer graphene (DMGr)/Cu composites.
• Ex-situ and in-situ Transmission Electron Microscopy (TEM) characterizations.

Main Results:

• Achieved a compressive strength of 1.56 GPa and plastic strain exceeding 0.6.
• Uniformly dispersed DMGr with sp2-sp3 hybridization facilitated interlayer sliding and mediated plastic deformation.
• Strong DMGr-matrix interactions impeded dislocation motion and promoted accumulation, enhancing strength and plasticity.

Conclusions:

• The developed DMGr/Cu composites demonstrate a successful strategy for mitigating the strength-ductility trade-off in nc metals.
• Interface nanostructuring is a viable approach for creating advanced materials with superior mechanical properties.
• Dislocation interactions and interlayer sliding are key mechanisms for achieving high strength and plasticity.