关键词: Al₂O₃-C不烧滑板材料, SiC聚合物前驱体, Zn粉, 强度, 显微结构

Abstract: This work aims at improving the medium- and low-temperature strength of Al₂O₃-C unfired slide plate materials.Sucrose,nickel nitrate hexahydrate,ethyl orthosilicate and oxalic acid aqueous solution with the mass ratio of 1∶0.15∶2.7∶0.03 were added to ethanol aqueous solution in turn,and dried at 110 ℃ for 18 h,obtaining SiC polymer precursor.Then,tabular corundum,α-Al₂O₃ micropowder and flake graphite were used as the main raw materials,added with the SiC polymer precursor and Zn powder,pressed at 150 MPa into green bodies of 150 mm×25 mm×25 mm,cured at 180 ℃ for 24 h,and then heat treated at 600,800,1 000,1 200 and 1 400 ℃ for 3 h under carbon embedded conditions.The effects of the SiC polymer precursor and Zn powder on the properties of Al₂O₃-C materials were studied.The results show that the Al₂O₃-C material has the optimal comprehensive performance when adding 4.5% SiC polymer precursor and 1.5% Zn powder;at low temperatures,Zn powder melts and forms metal bonding phases in the material system;at medium temperatures,the pyrolysis reaction of the SiC polymer precursor and the catalysis of Zn powder after evaporation make the system form SiC fiber bonding phases.They work together to give Al₂O₃-C unfired slide plate material high medium- and low-temperature strength,which overcomes the failure problem caused by the low strength in application.

Key words: alumina-carbon unfired slide plate materials, silicon carbide polymer precursor, zinc powder, strength, microstructure