SPARK PLASMA SINTERING (SPS) OF CARBON NANOTUBE (CNT) / GRAPHENE NANOPLATELET(GNP)-NICKEL NANOCOMPOSITES: STRUCTURE PROPERTY ANALYSIS

摘要

Carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) are attractive reinforcements for lightweight and high strength metal matrix composites due to their excellent mechanical and physical properties. The CNT/Ni (DM) nanocomposites exhibiting a tensile yield strength of 350 MPa (about two times that of nickel ～ 160 MPa) and an elongation to failure ～ 30%. In contrast, CNT/Ni (MLM) exhibited substantially higher tensile yield strength (～ 690 MPa) but limited ductility with an elongation to failure ～ 8%. GNP/Nickel nanocomposites were also processed via DM followed by SPS consolidation. The Ni-1vol%GNP nanocomposite exhibited the best balance of properties in terms of strength and ductility. The enhancement in the tensile strength (i.e. 370 MPa) and substantial ductility (～40%) of Ni-1vol%GNP nanocomposites was achieved due to the combined effects of grain refinement, homogeneous dispersion of GNPs in the nickel matrix, and well-bonded Ni-GNP interface effectively transfers stress across metal-GNP interface during tensile deformation.