The effect of rare earth CeO_2 on microstructure and properties of in situ TiC/Al-Si composite

摘要

In this work, CeO_2 is investigated as an additive for in situ preparation of TiC/Al-Si composite using exothermal dispersion (XD)+ casting technology. Experimental results show that CeO_2 at high temperature exhibits the same function as Ce, which is a kind of good modificator. When 0.5 wt. percent CeO_2 additive is added, the microstructure of eutectic silicon is significantly changed (the size is greatly reduced). Meanwhile, the amount of TiC particles is increased and the size is reduced. Compared with the composite without added CeO_2, the hardness value (HB) value, tensile strength and tensile elongation are greatly increased. However, under dry sliding friction test, weight loss of the composite is not significantly changed.