Microstructures and interfacial interactions of Al2O3 whiskers and graphene nano-platelets co-reinforced copper matrix composites
(1. School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China;
2. School of Materials and Environmental Engineering, Chengdu Technological University, Chengdu 611730, China;
3. Forschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung-Plasmaphysik, 52425 Jülich, Germany)
2. School of Materials and Environmental Engineering, Chengdu Technological University, Chengdu 611730, China;
3. Forschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung-Plasmaphysik, 52425 Jülich, Germany)
Abstract: The mechanical properties and microstructures of Al2O3 whiskers and graphene nano-platelets (GNPs) co-reinforced Cu-matrix composites were studied. Cu-matrix composites with a variation of GNPs amount were fabricated by mechanical alloying followed by vacuum hot-pressing sintering and hot isostatic pressing. The Cu-matrix composite with 0.5 wt.% GNPs (GNPs-0.5) suggests a good interfacial bonding of both Cu/C and Cu/Al2O3 interfaces. Both the hardness and compressive strength of Cu-matrix composites show a consistent tendency that firstly increases to a critical value and then decreases with increasing GNPs amount. It is suggested that the most possible strengthening mechanisms of both GNPs and Al2O3 whisker working in the Cu-matrix composites involve energy dissipating and load transfer, as well as grain refinements for GNPs. The synergetic effect of GNPs and Al2O3 whiskers is highlighted that the embedded GNPs would hinder the crack path generated at the Al2O3/Cu interface and enhance the already outstanding strengthening effect that Al2O3 whiskers provide.
Key words: graphene; Al2O3 whisker; Cu-matrix composite; microstructure; interfacial interaction