ホットプレスSi₃N₄-SiC複合焼結体の酸化挙動

抄録

The Si₃N₄-SiC composites which is composed of Si₃N₄ matrix doped with 2wt% Al₂O₃ and 5wt% Y₂O₃, and 50wt% SiC powder having a different mean particle sizes, were fabricated by hot-pressing. Their oxidation behavior was investigated and compared with the commercial Si₃N₄ sintered material. An oxidation test was carried out in an electric furnace at 1300°C for 100 hours. The measurement of bending strength, weight gain, surface roughness and microscopic observation of sintered materials were carried out after oxidation. Weight gain of the Si₃N₄-SiC composite was lower than that of the commercial Si₃N₄ sintered material. The crystalline phases of sintered materials after oxidation test were β-Si₃N₄, α-SiO₂, Y₂O₃⋅2SiO₂ and SiC. The bending strength of Si₃N₄-SiC composites slightly increased the value after oxidation.