Sm2O3掺杂对纳米莫来石前驱粉体微观结构和烧结性能的影响

为了改善纳米莫来石粉体烧结性能,以硫酸铝和硅酸钠为主要合成原料,添加不同含量Sm2O3,采用共沉淀工艺制备莫来石前驱粉体,经过煅烧得到莫来石纳米粉体,研究了Sm2O3掺杂量对莫来石粉体微观结构和烧结性能的影响.研究表明:当Sm2O3的加入量为4wt%时,合成温度可由传统的1300 ℃左右降低至1000 ℃,晶粒尺寸约为39 nm,比表面积达到95.265 m2/g.说明适当掺杂Sm3+对于合成纳米莫来石具有改善微观结构,促进烧结,促进莫来石晶相形成的作用.

Effect of Sm2O3 Doping on Microstructure and Sintering of Mullite Precursor Powders

The sodium silicate and aluminum sulfate powder are used as raw material, adding different contents of samarium oxide, the ultrafine mullite precursor powder is obtained by sodium metasilicate nonahydrate and aluminium sulfate octadecahydrate.The influence of amarium oxide doping content on the sintering of mullite is studied by scanning electron microscopy(SEM)and X-ray diffraction(XRD). The experiment results indicate that when the addition amount of Sm 2O3is 4wt%, the synthesis temperature can be decreased from 1300 ℃to 1000 ℃,the grain size is about 39 nm,and the specific surface area is 95.265 m2/g.The sintering of mullite increases with the amarium oxide doping addition and the crystalline state of the powder is more complete;proper doping the rare earth element samarium can improve the microstructure,promote sintering and the formation of crystalline phases of mullite.