FORMATION MECHANISM OF TiC IN Al/TiC COMPOSITES PREPARED BY DIRECT REACTION SYNTHESIS
(1.National Key Laboratory ofPreciseHeat Processing of Metal, Harbin Institute of Technology, Harbin 150001, P. R. China;
2.Jiamusi University, Jiamusi154002, P. R. China)
2.Jiamusi University, Jiamusi154002, P. R. China)
Abstract: The mechanism of reaction synthesis TiC in Al/TiC composites prepared by direct reaction synthesis(DRS) has been investigated in detail using quenching experiment, XRD and SEM. The results have shown that the reaction mechanism is a solution-precipitation mechanism, in which titanium dissolves into melted aluminium and reacts with carbon to form TiC, and then TiC particles precipitates out of the melt. It has also been shown that the processing of reaction synthesis TiC can be divided into three stages: melting of aluminium powder in the preform, formation and resolution of Al3Ti phase in the melted aluminium and the synthesis of TiC particles. Finally, a mechanism model of DRS to prepare Al/TiC has been established.
Key words: reaction composites Al/TiC microstructure mechanism