原位合成Al_2O_3/Ti-Al复合材料的研究

Research on Al_2O_3/Ti-Al Composite by In-Situ Process

利用氧对金属Ti、Al粉的部分氧化,原位合成了Al2O3/Ti-Al复合材料,通过XRD和SEM手段,发现Al2O3分布在Ti-Al基体交界处,在一些制得的复合材料中出现了大量原位生成的纤维。借助差热分析,对该制备过程的反应机理进行了初步探讨,研究认为该制备过程的反应步骤为:Ti、Al金属粉表面氧化→铝的熔化→TiAl3的生成→Ti2Al、TiAl、Ti3Al等多种化合物生成和Al对TiO2的还原反应。原始组成中铝含量决定了复合材料的主要晶相组成,铝含量不足时,生成Ti2Al、TiAl、Ti3Al等多种金属间化合物和氧化铝;铝含量足够时,最终的产物为TiAl3、金属铝以及氧化铝等相。

Al2O3/Ti-Al composite is prepared by in-situ process by use of Al -Ti system oxidized partly to produce Al2O3 and Ti - Al intermetallics. In some prepared samples lots of fiber are observed. This will have important value for the mechanical capabilities, Based on thermodynamics theories and existing calculation results, the reaction process is discussed. The process of reaction is as follows ： surface of Ti and Al being oxidized→melting of Al→forming TiAl3→forming other Ti - Al intermetallics and deoxidized of TiO2 by Al. When the content of Al is enough, TiAl3 ,Al2O3 and Al will be gained, otherwise, Ti2Al,TiAl, TiaAl and Al2O3 will be gained.