新型高效PM磷变质剂

A Novel and Effective PM Phosphorus Modifier

论述了一种新型高效的磷变质剂。试验结果表明 :用 PM对 Al-2 0 Si过共晶合金进行处理后 ,具有良好的变质效果 ,变质前 ,初晶 Si呈粗大六角形板片状 ,共晶 Si呈粗大针状 ,平均晶粒尺寸约为 2 50μm;变质后 ,初晶 Si和共晶 Si都很细小 ,呈块状和短棒状 ,晶粒尺寸干砂型为 4 0～ 50 μm,金属型为 2 0～ 30 μm。用 PM变质后 。

A novel and effective phosphorus modifier——PM is studied.The results show that PM has a good modification effect on Al 20Si hypereutectic alloy.Before modification,the primary Si phase with bulky hexagonal plate and eutectic Si phase with coarse acicular appearance.Average grain size of primary Si phase is about 250 μm.After modification,both primary Si phase and eutectic Si phase appear nubbly and club shaped respectively.Average grain size is 40~50 and 20~30 μm in dry sand mold and permanent mold respectively.Hydrogen content decreases in the melt with PM modification treatment and the mechanism of PM modification is analysed.