Wybrane właściwości kompozytów na bazie ZrB_2, otrzymanych metodą SPS i przeznaczonych na części maszyn do kształtowania elektroerozyjnego

摘要

The effect of the addition of silicon carbide and boron carbide powders on the properties of ZrB_2 ceramic composites constituting UHTC materials (ultra high temperature ceramics) was investigated. Polycrystalline zirconium boride samples as well as matrix composites of this phase with addition of 2 and 10 wt.% SiC and B_4C were obtained by pressure-assisted sintering using SPS/FAST (spark plasma sintering/field assisted sintering technique) in the temperature range of 1800÷2000°C. Samples were characterized by X-ray diffraction, scanning electron microscopy, hardness and fracture toughness. The obtained materials are characterized by a high relative density in the range of 97÷98%. Higher hardness and fracture toughness were observed for the composite obtained in temperature 1900°C.