Effect of CeO₂ Size on Microstructure, Synthesis Mechanism and Refining Performance of Al-Ti-C Alloy

The effects of CeO₂ size on the microstructure and synthesis mechanism of Al-Ti-C alloy were investigated using a quenching experiment method. A scanning calorimetry experiment was used to investigate the synthesis mechanism of TiC, the aluminum melt in situ reaction was carried out to synthesize master alloys and its refining performance was estimated. The results show that the Al-Ti-C-Ce system is mainly composed of α-Al, Al₃Ti, TiC and Ti₂Al₂₀Ce. The addition of CeO₂ obviously speeds up the progress of the reaction, reduces the size of Al₃Ti and TiC and lowers the formation temperature of second-phase particles. When the size of CeO₂ is 2-4 μm, the promotion effect on the system is most obvious. The smaller the size of CeO₂, the smaller the size of Al₃Ti and TiC and the lower the formation temperature. Al-Ti-C-Ce master alloy has a significant refinement effect on commercial pure aluminum. When the CeO₂ size is 2-4 μm, the grain size of commercial pure aluminum is refined to 227 μm by Al-Ti-C-Ce master alloy.