Abstract
Yttrium α-Sialon ceramics have been fabricated by reaction-bonding method, which offers low sintering shrinkage and is a low cost process. The green compacts fabricated from starting materials of Si, Y2O3, Al2O3 and AlN were nitrided at 1350°C and post-sintered at 1700-1900°C in nitrogen atmosphere. In the samples sintered at 1900°C, relative density was high (98%) and the grains became elongated. The mechanical tests showed that yttrium α-Sialon ceramics with elongated grains produced by reaction-bonding process exhibit high hardness (17GPa) and high fracture toughnes (5 Mpam1/2).
