FENG Chonglong, LIU Weiliang, LI Yangcheng, ZENG Xiaojun, XU Zhaoliang
(Jingdezhen Ceramic Institute, Jingdezhen 333001, Jiangxi, China)
Abstract: B4C ceramic film was prepared by aqueous tape-casting with boron carbide powder as starting material, Al2O3 and Y2O3 as sintering aids, Polymine (PEI) as dispersant, polyethyleneglycol (PEG) as plasticizer, poval (PVA) and gelatin as binder respectively. The influences of pH, dispersant content, the kinds and content of binder on rheological property and the effect of the sintering temperature on the microstructure and mechanical properties of B4C ceramic composites were studied. The experimental results indicated that, in acid medium, the slurry with good stability and rheology could be prepared with 1.0 wt.% PEI, 5.0 wt.% PVA or 7.0 wt.% gelatin. Cast film had better flexibility and strength with PVA as binder, and gel property with gelatin as binder. The results indicated that the best mechanical properties of B4C ceramic composites were achieved when the sintering temperature was 2000°C, the relative density, bending strength, fracture toughness and vickers hardness of the composites were 98.4%, 513.19 MPa, 6.58 MPa • m1/2, 38.6 GPa, respectively.
Key words: B4C; ceramic film; aqueous tape-casting