原料组份、粒度对Ti-C-Fe体系自蔓延高温合成的影响

Effect of Particle Size and Content of Raw Materials on Self-Propagating High-Temperature Synthesis of Ti-C-Fe System

本文探讨了Fe含量、碳源及Ti、C颗粒大小对Ti－C－Fe体系自蔓延高温合成过程及产物结构特征的影响．结果表明：Fe含量增高，燃烧温度降低，产物颗粒变细，而燃烧波速度在10wt％Fe时出现极大值，反映了Fe液相的作用．石墨作碳源燃烧合成的TiC更接近于化学计量的TiC，且TiC颗粒较粗，燃烧温度、燃烧波速度均较高，反映了碳源结构差异对燃烧合成的影响．Ti、C颗粒越细，越有利燃烧反应合成．随着Fe含量增高，Ti－C－Fe体系燃烧方式由稳态变为振荡式及螺旋式燃烧．Fe含量＞60wt％；反应则不能自持．

The effects of Fe content, carbon sources and the particle size of Ti and C on the SHSprocesses of Ti-C-Fe and structure charactristics of synthesized powders were studied. It is shownthat combustion temperature becomes lower and particle sizes of synthesized product becomesmaller with the increasing of Fe content and the velocity of combustion wave is highest at 10wt%of Fe content. This is due to the effect of Fe liquid. The composition of TiC synthesized withgraphite is more close to the stoichiometric TiC, the size of TiC particles is larger and combustiontemperature and velocity of combustion wave are higher than with carbon black. The structuredifference between the two kinds of carbon is responsible for the effect of carbon. Smaller Tiand C particle sizes do good to combustion synthesis of the system. With the increasing of Fecontent the combustion model becomes pulsating and spin combustion from steady combustion.The combustion reaction for the system can'nt sustain if Fe content is higher than 60wt%.