磷元素对Al-Mg_2Si合金显微组织的影响

Microstructure Study of Al-Mg_2Si Alloy by the Modification of P Addition

研究了P元素的加入对Al Mg2Si合金组织的影响.结果表明:在常规铸造条件下,Al Mg2Si合金中初晶Mg2Si为粗大的多角形块状.经过P元素变质后合金中的初晶Mg2Si得到明显细化,并成为分布较均匀的块状或球团状,当加入的P元素量为 0. 5%时,初晶Mg2Si最细小、圆整.其实质是P元素与Mg元素形成的Mg3 (PO4 )2化合物充当了Mg2Si的形核核心.

The influence of P element on the structure of Al-Mg_2Si alloy has been studied. The results show that the primary Mg_2Si phase of Al-Mg_2Si alloy is solidified into large polygonal shape on ordimary condition. After P element is added in the Al-Mg_2Si alloy, the polyhedral primary Mg_2Si becomes rod-like or granular and its distributing becomes more uniform. When P element addition is 0.5wt%, finer primary Mg_2Si crystals are obtained.The reason is that compound Mg_3(PO_(4))_2becomes the core of primary Mg_2Si.