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在材料的自蔓延高温合成(SHS)过程中,反应物与产物之间,各种结构层次(宏观、微观、晶体结构等)上的转变过程—结构宏观动力学,对材料制备具有决定意义。本文分别在宏观结构和微观结构两个层次上研究了Al-TiO_2自蔓延高温合成系统的结构宏观动力学。结果表明:在宏观结构上,随着样品尺寸加大,如工艺控制不当会出现三种主要的宏观结构缺陷:气孔增加,偏析加剧、宏观裂纹。材料的显微结构,是由燃烧波内一种非均匀网络状过渡组织转变而来的。
In SHS process, the transition process between the reactants and products, the various structural levels (macroscopic, microscopic, crystal structure, etc.) -structural macroscopic kinetics is of decisive significance for the material preparation. In this paper, macroscopic structure and microstructure at two levels were studied Al-TiO 2 self-propagating high temperature synthesis of the system macroscopic kinetics. The results show that there are three main macrostructural defects in the macroscopic structure, such as increased porosity, segregation and macroscopic cracks, as the sample size increases. The microstructure of the material is transformed by a non-uniform network-like transitional structure in the combustion wave.