Effect of CeO(2) on Microstructure and Synthesis Mechanism of Al-Ti-C Alloy

The effects of CeO(2) on the microstructure and synthesis mechanism of Al-Ti-C alloy were investigated by quenching experiment method, while using Al powder, Ti powder, graphite powder, and CeO(2) powder as main raw materials. The results showed that the addition of CeO(2) was favorable for promoting the formation of TiC particles in Al-Ti-C systems. With CeO(2) contents increasing, the distribution of TiC particles were more homogeneous, and the rare earth phase Ti(2)Al(20)Ce was formed. CeO(2) had little effect on the synthesis of Al(3)Ti particles in Al-Ti-C systems, but had a significant effect on the synthesis of TiC particles. In the Al-Ti-C system, TiC is mainly formed by the reaction of dissolved [Ti] and solid C in the melt. While in the Al-Ti-C-Ce system, CeO(2) reacts with C and O(2) to form CeC(2) firstly, and then CeC(2) reacts with dissolved [Ti] to form TiC. Based on thermodynamic calculation and microstructure analysis in the process of reaction, a macroscopic kinetic model of Al-Ti-C-Ce system reactions was proposed in this paper.