The effect of rare earth （RE） elements on the morphologies and sizes of Si phases in the hypereutectic A1-Si alloys modified with P was investigated. The results show that the addition of La element to the hypereute...The effect of rare earth （RE） elements on the morphologies and sizes of Si phases in the hypereutectic A1-Si alloys modified with P was investigated. The results show that the addition of La element to the hypereutectic A1-Si alloys can enhance the effect of P element on the modification of the primary Si phases. In the multiplex modification of RE-P, the primary Si phase is refiner and the shape of the eutectic Si is changed from long needle-like to short rod-like. Moreover, the agglomeration rate of the primary Si phase is slowed greatly. Even the melt is held for 6 h, the average size of the primary Si phase is still satisfied. The results analyzed by scanning electron microscope （SEM） indicate that La is richer at A1-Si interface than that in α-A1 or primary Si phase. The higher the La content in the A1-Si interface, the smaller the primary Si phase.展开更多
基金supported by the National Natural Science Foundation of China （Grant No.50075051）
文摘The effect of rare earth （RE） elements on the morphologies and sizes of Si phases in the hypereutectic A1-Si alloys modified with P was investigated. The results show that the addition of La element to the hypereutectic A1-Si alloys can enhance the effect of P element on the modification of the primary Si phases. In the multiplex modification of RE-P, the primary Si phase is refiner and the shape of the eutectic Si is changed from long needle-like to short rod-like. Moreover, the agglomeration rate of the primary Si phase is slowed greatly. Even the melt is held for 6 h, the average size of the primary Si phase is still satisfied. The results analyzed by scanning electron microscope （SEM） indicate that La is richer at A1-Si interface than that in α-A1 or primary Si phase. The higher the La content in the A1-Si interface, the smaller the primary Si phase.
