Spark plasma sintering of layered γ-Al2O3/graphene reinforced nanocomposites

Abstract

Multi-layered ceramic composites with alternation of grain sizes in layers were produced by adding thin interlayers of graphene-augmented alumina nanofibres (GAIN) between layers of monolithic α-Al2O3. The composite was mounted layer by layer directly in the graphite mould, using a vacuum filter system to precipitate alumina nanopowder and GAIN layers from the corresponding suspensions. The 30-mm diameter samples were consolidated by the spark plasma sintering technology at 1450 °C in nitrogen atmosphere at 50 MPa pressure. The effect of interlayers on the microstructure of alumina and on the thermal and electrical conductivity of the compact is studied.