Al-TiO2-C体系中XD反应动力学机制的研究

采用热分析和显微组织分析的方法,研究了在XD工艺条件下Al-TiO₂-C体系的反应机制。合成反应剧烈的放热效应在试样内部形成的高温冶金微区促进增强粒子的合成及基体的合金化。反应在不同阶段有不同的反应机制,在快速反应阶段主要以溶解-析出-破裂机制进行,快速反应伴随的剧烈的放热效应在粒子内部产生的热应力是反应物破裂的主要原因。反应物的破裂加快了反应速度,细化了生成的增强粒子。 

KINETIC MECHANISM OF THE XD REACTION IN Al-TiO2-C SYSTEM

The kinetic mechanism of XD reaction in Al TiO 2 C system was studied in this paper. Result shows that a strong exothermic reaction results in the formation of a high temperature metallurgical micro region in the sample, which is favorable to synthesis of reinforcing particles TiC p / (Al 2O 3) P and in matrix alloying. Synthetic reactions take place as different kinetic mechanisms in different periods. There exists a crack of the reactants during the quick reaction period,the cracking was caused by the steep temperature gradient and great thermal stress inside the reactants. The cracking of reactants makes the reaction speed very fast and synthesized particles (Al 2O 3) P and TiC P very fine.