EXPERIMENTAL STUDY ON REACTION SYNTHESIS OF TiC IN Al-Ti-C SYSTEM

The reaction process and mechanistn of reaction synthesis of TiC in Al-Ti-C system have been investigated in detail by observing the microstructure of the water quenched preform with SEM and EDX. The results showed that the reaction processing can be divided into three stages: aluminium powder is melted firstly, then titanium dissolves in the melted aluminium and Al3Ti is formed around titanium powder, titanium concentrates around carbon powder and a Ti-rich layer is observed around carbon pariicles,in which titanium atom reacts with carbon atom to synthesize TiC;TiC precipitates out of the melt, and diffuses out of the layer. A solution-precipitation mechanism and a reaction model were set up based on the experimental results.