Effect of Rare Earth Ce on Refining Effect of TiC Refiner for Aluminum

Using industrial pure aluminum, 5 μm TiC powder and rare earth Ce as raw materials, aluminum ingots were prepared by casting in a metal mold and adjusting the contents of TiC and Ce. The microstructure was observed by OM and SEM, and the density, electrical conductivity and microhardness were tested. The results show that when the addition amount of TiC is 0.1%, 0.2%, 0.3% and 0.4%, the optimal amount of Ce is 0.4%, 0.4%, 0.3% and 0.3%, respectively. Compared to the grain size of the samples without TiC and Ce, that of the samples with TiC and Ce is decreased by 1.71, 1.50, 1.26 and 1.31 times, respectively. The relative densities and microhardness of the prepared samples are improved, with the relative density of more than 99%, and the microhardness is up to 144.6 HV, which is increased by 16% and 44.3% compared with the original samples, respectively. Meanwhile, the electrical conductivities have a little change. The optimal addition amount of TiC and Ce is 0.1% and 0.4%, respectively. At the time, rare earth forms rare earth compounds, which promotes the refining effect of TiC.