Work-function-tuned Ag/Ni coated graphene for enhanced conductivity and strength in aluminum composites

Simultaneously enhancing the mechanical strength and electrical conductivity of aluminum-matrix composites remains challenging because conventional strengthening strategies usually introduce defects and interfaces that intensify electron scattering. In this work, graphene surfaces were coated with Ag or Ni via electroless deposition to regulate the graphene/Al interface through work-function differences. Few-layer graphene was coated with Ag (lower work function than graphene) or Ni (higher work function than graphene) via electroless deposition, dispersed into aluminum powders by ball milling, and consolidated by high-pressure sintering at 1 GPa. The Ni-coated graphene/Al composite achieves an ultimate tensile strength of 336 MPa, corresponding to a 78.7% increase over identically processed pure aluminum. In contrast, the Ag-coated graphene/Al composite delivers an electrical conductivity of 73.37% IACS, representing a 17.58% improvement relative to the pure aluminum, while maintaining a high ultimate tensile strength of 318 MPa. The optimization of the ultimate tensile strength and conductivity follows distinct pathways, governed respectively by interfacial phase-architecture strengthening and work-function-induced electronic doping. This strategy offers a scalable route for synergistically regulating interfacial phases and electronic structures toward high-strength and high-conductivity aluminum-matrix composites for structural–functional integration. Download: Download high-res image (322KB) Download: Download full-size image