固相反应合成Al_4SiC_4材料

Synthesis of Al_4SiC_4 by solid reaction

采用粒度14μm的磨料级碳化硅,粒度10μm的工业级金属铝粉和粒度5μm的工业级炭黑粉为原料,按SiC∶Al∶C质量比为22∶59∶19配料制成试样,在氩气保护下,分别在1200℃8h、1600℃2h和1650℃2h烧成,研究了通过固相反应合成Al4SiC4材料的条件和动力学过程。通过X射线衍射仪进行物相分析,扫描电子显微镜和透射电子显微镜的形貌分析以及能谱分析确定成分。结果表明:反应体系在1200℃以下,铝和炭黑反应首先生成中间相Al4C3;从1200℃开始通过SiC+Al4C3=Al4SiC4固相反应生成Al4SiC4;当合成温度达到1650℃时,获得Al4SiC4材料;制备的Al4SiC4材料的颗粒均匀,尺寸在几百纳米到几微米之间。

The conditions necessary for synthesizing Al4SiC4 from mixtures of AI powder（ 10 μm）, SiC powder（ 14 μm） and carbon black（5 μm）,as starting materials, and the synthesizing dynamic process by solid reaction were examined in the p, present study. The specimens with the mass ratio of m（ SIC）： m（ Al）： m（C） being 22 ：59 ： 19 were prepared and fired at 1200 ℃ for 8 h, 1600 ℃ for 2 h and 1650 ℃ for 2 h respectively in Ar atmosphere. The phase compositions of the specimens were determined by X-ray diffractometry （XRD）, the microstructures were examined by scanning electron microscope （SEM） and the transmission electron microscope （TEM）,and the elemental and quantitative compositions of the specimens were determined by the energy dispersive X-ray spectroscopy （EDX）. The results showed that Al4C3 as intermediate product formed by the reaction ：,between metal Al and C at below 1200℃, and the solid reaction, i. e., SiC （s） ＋ Al4C3 （s） =Al4SiC4 （s） , began at 1200 ℃ forming Al4SiC4. At 1650 ℃,Al4SiC4 was obtained. The particle Of Al4SiC4 is uniform with the size from several hundreds of nanometers tO several microns determined bY means of SEM and TEM imaqes.