机械诱发自蔓延反应合成Ti_3AlC_2的机理研究

Reaction mechanism for the synthesis of Ti_3AlC_2 by mechanically induced self-propagation reaction

以3Ti/Al/2C粉体为原料,采用机械合金化的方法以合成Ti3AlC2材料。研究结果表明,在机械合金化过程中诱发自蔓延反应,反应会产生大量坚硬的小块体颗粒,大小约为0.2～11mm。粉体的组成相为TiC、Ti3AlC2、Ti2AlC,而块体仅含有TiC和Ti3AlC2。获得的粉体和块体产物中Ti3AlC2含量分别约为63wt%和84.8wt%。提出了一个机械诱发自蔓延反应合成Ti3AlC2的反应机制,即Ti3AlC2是从固相TiC与Ti-Al液相中形核并长大。

3Ti/Al/2C elemental powders were used as the starting materials for the synthesis of Ti3AlC2 powders by mechanical alloying. The result shows that a mechanically induced self-propagation reaction is triggered during mechanical alloying of 3Ti/Al/2C powders. After reaction, amounts of rigor bulk particles with the size of 0.2-11 mm were produced. The powders were composed of TiC, Ti3AlC2 and Ti2AlC. But the bulks product only contained TiC and Ti3AlC2. The Ti3AlC2 content of the powders and bulks was 63wt% and 84.8wt%, respectively. A reaction mechanism for the synthesis of Ti3AlC2 by mechanically induced self-propagation reaction was proposed. The mechanism suggested that Ti3AlC2 might be formed from Ti-Al liquid and solid TiC.