Al2O3/SiO2纳米复合陶瓷型芯材料的制备与性能

用粉体分散及热压注方法制备了Al2O3/SiO2纳米复合陶瓷型芯材料，研究了Al2O3/SiO2纳米复合陶芯材料的增强机理，SiO2纳米粉在Al2O3微粉基体中较均匀分布，不含纳米粉材料的断裂方式为典型的沿晶断裂，SiO2含量为3％和5％时，为沿晶／穿晶混合断裂，SiO2含量为7％时，以穿晶断裂为主，加入SiO2纳米粉后，复合材料的孔洞减少，致密度增加，致使烧结温度降低，含7％SiO2纳米粉的陶芯强度比不含纳米粉的提高了约4倍，其原因是纳米晶的析出和材料断裂方式的改变。

PREPARATION AND PROPERTIES OF Al2O3/SiO2 CERAMIC CORE NANO-COMPOSITES

By proper dispersion and hot pressing injection of the mixture, the Al2O3/SiO2 ceramic cores nano-composites were prepared, and the strengthening mechanism were studied. The results showed that the nano SiO2 distributed uniformly in the microcrystaHine Al2O3 matrix. The fracture mode of the Al2O3/SiO2 ceramic cores without the nano SiO2 is the typical intergranular fracture. The fracture mode of the Al2O3/SiO2 ceramic cores with 3% and 5% (mass fraction) nano SiO2 is the intergranular/transgranular mixed fracture, and is mainly transgranular fracture for that with 7% nano Si02. The pore ratio of the nano-composites decreased and the density increased after the nano SiO2 was added, which decrease the sintering temperature of the ceramic core. The bending intensity of the ceramic core was improved about four times when the 7% nano SiO2 was added. The strengthening mechanism of the Al2O3/SiO2 ceramic core nano-composites is the separate out of the nano-crystal and the change of the fracture mode.