论文部分内容阅读
采用P和稀土La对过共晶Al-Si合金进行变质处理,研究了P和La对过共晶Al-Si合金微观组织的影响。结果表明,加入P后,合金中初生Si相明显细化,由粗大的块状变为形貌圆整的小颗粒状,且数量增多,分布均匀。当P加入量为0.06%(质量分数)时,初生Si的平均尺寸达到最小,从未变质时的122μm下降到25μm。而当P加入量为0.09%时,初生Si的平均尺寸反而变大,出现过变质现象。在P、La复合变质时,加入0.9%的La对共晶Si的变质效果最好,当La加入量增加到1.2%时,出现过变质现象。
The microstructure of hypereutectic Al-Si alloy was studied by using P and rare earth La to modify the hypereutectic Al-Si alloy. The results show that after addition of P, the primary Si phase in the alloy is obviously refined, from coarse massive to small granular with round and round shape, with an increasing number and uniform distribution. When the addition amount of P is 0.06% (mass fraction), the average size of primary Si is the smallest, from 122μm without modification to 25μm. However, when the amount of P added is 0.09%, the average size of primary Si instead becomes larger and the phenomenon of metamorphism appears. In the P and La compound metamorphism, the addition of 0.9% La has the best effect on the modification of eutectic Si. When the amount of La added increases to 1.2%, metamorphism occurs.