热爆反应合成AlN-SiC材料

Thermal explosion synthesis of AlN-SiC materials

采用Al、Si粉和C0.36N0.64粉末为原料,通过化学炉诱发热爆反应合成技术,制备AlN-SiC固溶体粉体。采用XRD和SEM确定合成试样的物相组成和观察样品的显微形貌。研究结果表明,通过热爆反应可合成AlN-SiC固溶体材料,当原料中C0.36N0.64粉末过量时,可合成单相AlN-SiC固溶体材料。样品由许多六角片状细小晶粒和尺寸较大的AlN-SiC固溶体晶粒组成,晶粒边长分别约为1.5μm和20μm。结合动力学和热力学分析,讨论了热爆反应合成AlN-SiC固溶体的反应合成机理。C0.36N0.64先发生分解生成N2和C,然后,Al与N2反应,生成AlN,反应放出大量的热,诱发热爆反应的发生。最后,AlN与Si、C反应,或Si3N4与C和N2反应,生成AlN-SiC固溶体。

AlN-SiC solid-solution materials were fabricated by chemical oven induced thermal explosion using Al, Si and C0.36N0.64 powders as raw materials. The phase composition of the synthesized samples was determined by XRD. The morphology of the sample was observed by SEM. The results show that AlN-SiC solution materials can be synthesized by thermal explosion. The single phase AlN-SiC solid-solution materials may be obtained by adding excessive C0.36N0.64 powders. The sample contains many hexagonal platelets AlN-SiC solid-solution grains with the edges length of 1.5 and 20 μm, respectively. The reaction mechanism for synthesizing of AlN-SiC solid-solution was researched by combining thermo- dynamics and kinetics analysis. At first, the C0.36N0.64 is decomposed to C and N2, and then, Al reacts with N2 to form AlN releasing amounts of heat which induces the occurrence for thermal explosion reaction; finally, AlN reacts with Si and C, or Si3N4 reacts with C and N2 to form AlN-SiC solution.