SiC nano-powders, produced via laser and plasma synthesis were processed to obtain fully dense and nano-sized materials, with a grain size ranging from 80 to 150 nm. Densification was achieved through hot pressing, adding alumina and yttria as sintering aids, as used in conventional liquid phase sintered SiC from commercial powders. Different processing conditions were tested and compared to optimize the process. The densification behaviour was studied. The microstructure was analyzed by scanning and transmission electron microscopy. Vickers hardness, fracture toughness, Young modulus and bending strength were measured on dense samples. Mechanical tests show that, the properties of these nano-materials are comparable to those of sub-micrometre grain-sized SiC materials.

Keywords: Nanoceramics, Silicon carbide, Densification behaviour, Microstructure, Mechanical properties