材料期刊网

以Mg、Al、TiO2和B2 O3粉体为原料,采用自蔓延高温合成法合成了 MgAl2 O4和 TiB2复合粉体,用稀硝酸除去产物中的TiB2及残余反应物后,获得了较高纯度的MgAl2 O4。然后用MgO 部分取代 Mg 研究了不同Mg源对合成产物的影响,用XRD和SEM检测了两组反应获得的MgAl2 O4粉体,用激光粒度测试仪分析了产物的粒径大小及分布,用红外光谱仪测试了粉体性能较佳的反应酸洗产物的红外透光率。结果表明,以单一Mg 粉为Mg源时,MgAl2 O4的相对含量为85．96％,且颗粒较小,平均粒径为5．36μm,粒径分布较集中,0．1~10μm 的颗粒占80．68％；以(Mg＋MgO)为Mg源时,MgAl2 O4的相对含量为71．55％,且颗粒较大,平均粒径为11．18μm,粒径分布较分散,0．1~10μm的颗粒占54．96％；综合考虑,以Mg为镁源获得的MgAl2 O4粉体性能好,经红外光谱分析,可得,MgAl2 O4透过率高,透过波段范围宽,在1100~2978 cm－1之间的红外透过率达到50％以上,高透光率的镁铝尖晶石具有低的辐射率,可应用于红外隐身材料。

The composite powders of MgAl2 O4 and TiB2 were prepared by self-propagating high-temperature synthesis method with Mg powder,Al powder,TiO2 powder and B2 O3 powder as raw materials.Then relative-ly high purity magnesium aluminate spinel powders were obtained after ultrasonic pickling by using 20wt% ni-tric acid to remove TiB2 and residual reactants in the product.The effect of different magnesium sources on the product was studied by MgO partially replacing Mg;the productivity and the particle size of the two reaction system were analyzed in contrast by XRD and SEM.And also the purity of MgAl2 O4 after acid pickling was studied.The results show that MgAl2 O4 in the products account for 85.96% with Mg as magnesium source,the particles are fine with average particle size 5.36μm and 80.68% of the particles range from 0.1 to 10μm;MgAl2 O4 in the products account for 71.55% with Mg and MgO as magnesium source,the particles are relatively large with average particle size 11.18μm and the particle size distribution is relatively wide as 54.96% are in the range of 0.1-10μm.Reaction products MgAl2 O4 without MgO addition have high transimittance and wide wavelength range as the transmittance of MgAl2 O4 reaches more than 50% between 1 100 and 2 978 cm-1 .MgAl2 O4 of high transimittance has low radiation,so it can be used as infrared stealthy materials.