【摘要】 以V、Al和C粉体为原料,采用热爆合成技术制备V2AlC材料,并对V-Al-C体系进行了热力学分析,利用X射线衍射和扫描电镜对合成产物进行了相组成和产物形貌分析,探讨了热爆反应合成V2AlC材料的反应机制。结果表明,V-Al-C体系的绝热燃烧温度达2767K;2V/Al/C粉体热爆合成产物的主相为V2AlC,并含有少量的VCx和AlV3;原料中添加过量的Al,可消除AlV3副产物,并显著地促进V2AlC反应合成;2V/1.3Al/C热爆产物中V2AlC呈片状和板条状两种晶体形貌,长度大约为10μm;热爆反应合成V2AlC的机制为VC与V-Al共晶液相反应合成V2AlC。更多还原

【Abstract】 The V2AlC was synthesized by thermal explosion using 2V/Al/C powders.V-Al/C system was analysized by thermodynamic.The phase composition and morphology of the products were analysized by XRD and SEM.The reaction mechanism form synthesis of V2AlC was studied.The results show that the adiabatic temperature of V-Al-C system was 2767 K.The majority products were V2AlC in the synthesized sample.Small amounts of VCx and AlV3 also can be found.Adding excess Al in the raw materials can remove AlV3 phase,enhancing the synthesis of V2AlC.Two kinds of V2AlC grain(lath and platete) morphology can be found in the products.These grains had a length of about 10 μm.One reaction mechanism for synthesizing V2AlC can be proposed.The mechanism suggested that V2AlC might be formed from V-Al liquid and solid VC.更多还原