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以激冷法制得的高纯、超细金属铝粉和化学纯试剂TiO_2为原料,通过对燃烧过程的观察分析和结构、成分、化学状态分析,研究了Al-TiO_2自蔓延高温合成(SHS)反应的机理。结果表明,反应分三阶段:反应前期、反应期、产物反应期。反应前期主要反应是液态铝表面氧化膜分解。反应期则发生Al与TiO_2的界面反应,并诱发TiO_2颗粒链式劈裂效应,使反应速度成倍增长,最后反应放出足够的热量将TiO_2熔化,使反应以燃烧的形式进行,合成Ti、Al_2O_3。最后是合成产物进一步反应形成微量TiO、TiO_2。
Based on the observation and analysis of the combustion process and the analysis of the structure, composition and chemical state of the as-prepared high purity ultrafine metal aluminum powder and chemically pure reagent TiO 2, the effects of SHS, Reaction mechanism. The results show that the reaction is divided into three stages: the pre-reaction period, the reaction period, the product reaction period. The main reaction during the early reaction is the decomposition of the oxide film on the liquid aluminum surface. During the reaction period, the interfacial reaction between Al and TiO_2 occurs, and the chain-splitting effect of TiO_2 particles is induced to double the reaction rate. Finally, the reaction releases enough heat to melt the TiO_2 to make the reaction proceed in a combustion mode to synthesize Ti and Al_2O_3 . Finally, the synthesized product further reacted to form trace amounts of TiO and TiO 2.