化学炉自蔓延高温合成AlB2粉体

AlB_2 powders prepared by self-propagating high-temperature synthesis with chemical oven

以Al和B为原料,探究利用化学炉自蔓延高温合成Al B2的新方法。根据热力学基本原理,对化学炉自蔓延高温合成Al B2的绝热燃烧温度进行数值计算,利用XRD和FESEM分别研究合成产物的物相组成和显微组织。结果表明:利用化学炉自蔓延高温合成技术可以成功制备Al B2;常温下Al-B体系的绝热燃烧温度Tad仅为1 261 K;只有当预热温度在1 000 K以上时,才可以实现自蔓延燃烧,燃烧温度Tc为2 053 K;此外,合成产物中还含有杂质相Al B12和残留的Al。

A novel method for synthesizing Al B2 powders by chemical oven self-propagating high-temperature synthesis（C.O.SHS） was studied. The adiabatic temperature of Al B2 prepared by C.O.SHS was calculated based on the principles of thermodynamics. The phase composition and microstructure of the synthesized products were analyzed by XRD and field emission SEM. The results show that Al B2 powders can be successfully synthesized from the mixtures of Al and B by C.O.SHS technique. The adiabatic temperature Tadof Al B2 prepared in Al-B system at room temperature is only 1 261 K. The synthesis can not self-sustain unless increasing the preheating temperature up to 1 000 K,and the combustion temperature Tcis 2 053 K. In addition,there is the impurity phase Al B12,and the combustion synthesis has incompleteness due to the residues of Al in the final products.