中文摘要：

研究了稀土La对铝镁合金凝固区间和微观组织的影响。结果表明，La对铝镁合金凝固区间和微观组织有、明显的影响。加入La，合金凝固区间变大、凝固时间增加，合金流动性能得到改善。La的加入对合金有变质作用，晶粒数量增多，尺寸变小，形貌圆整。

英文摘要：

The effects of RE La on the solidification range and the microstructure of A1-Mg alloy were researched. The results indicate that the addition of RE La can significantly impact on the solidification range and the microstructure. The addition of RE La can enlarge the alloy solidification range and increase its solidification time and its flow performance also get great improvement. The addition of RE La has the metamorphism effect on A1-Mg alloy, the grain number gets increase, the grain size get smaller and its morphology becomes rounder.