关键词: 锆刚玉, Al₂O₃-SiC-C, 强度, 抗热震性, 抗氧化性, 显微结构

Abstract: Al₂O₃-SiC-C materials were prepared using recycled corundum (1-3 and 3-5 mm),white fused corundum (≤1 mm),α-Al₂O₃ micropowder (≤10 μm),flake graphite (≤50 μm) and silicon carbide (≤1 mm) as main starting materials,silicon powder (≤74 μm) as the antioxidant,and thermosetting phenolic resin with a carbon residue of about 45 mass% as the binder.The effects of the zirconia corundum (AZ40,≤74 μm) addition (0,3%,6%,9% and 12%,by mass) on the structure and properties of the Al₂O₃-SiC-C materials were investigated.The fracture morphology of the samples after heat treatment was observed using a field emission scanning electron microscope,and the structure was analyzed.The results show that:(1)with the increase of the AZ40 addition,the bulk density,cold modulus of rupture,cold compressive strength,hot modulus of rupture,and the retention ratio of the cold modulus of rupture of the samples all increase first and then decrease,while the apparent porosity and oxidation index change in reverse;(2)with the AZ40 addition increasing to 12%,the sample performs lower mechanical and antioxidant properties than that without AZ40,indicating that an appropriate AZ40 addition is beneficial to improving the mechanical properties,thermal shock resistance and oxidation resistance of the Al₂O₃-SiC-C materials;(3)the sample with 3% AZ40 exhibits the best comprehensive performance.

Key words: zirconia corundum, Al₂O₃-SiC-C, strength, thermal shock resistance, oxidation resistance, microstructure