Sol-gel synthesis of SiC@Y3Al5O12 composite nanopowder and preparation of porous SiC-ceramics derived from it

摘要: Abstract A sol-gel method with aluminium and yttrium alkoxoacetylacetonates as precursors was used to modify highly dispersed silicon carbide powder, the formation of SiC@Y3Al5O12 a low content Y3Al5O12 ∼2 vol%. Two series porous carbide-based ceramics were produced by spark plasma sintering (SPS) SiC powders at temperatures 1,400–1,700°С (exposure time 5 min) pressures 47 58 MPa. The relative density 38–51 26–49% for materials obtained without modification, respectively. It shown that greatest influence additive on compaction process observed elevated SPS 1,600–1,700°С. This related easier sliding particles during high-temperature sintering, due liquid Al2O3-Y2O3-SiO2 film their surface under given temperature conditions. significant (by 2.5 times) increase in compressive strength modified samples, compared based an individual, maximum (1,700 °C); microhardness value rose sharply 5.9 1,600 °C. effect pressure 1,500 °C not so significant, this mainly samples liquid-phase SiC@Y3Al5O12.