P、La变质处理对过共晶Al-Si合金的影响  

Effects of P and La Modification on Silicon Phase in Hypereutectic Al-Si Alloy

作　　者：武宏发 程和法[1] 秦晓雄 徐通[1] 张军[1] Wu Hongfa Cheng Hefa Qin Xiaoxiong Xu Tong Zhang Jun(College of Materials Science and Engineering, Hefei University of Technolog)

机构地区：[1]合肥工业大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2017年第9期1037-1040,共4页Special Casting & Nonferrous Alloys

摘　　要：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 hypereutectic Al-20 Si alloys were modified by P and rare earth element La,and effects of P and La on the modification of primary silicon phase in the alloys were investigated.The experimental results indicate that the addition of P can refine greatly primary silicon phase in hypereutectic Al-20 Si alloy.The primary silicon phase in modified alloys is changed into fine granule from coarse block shape in unmodified alloys and well-distributed in matrix.The optimal refinement on the primary silicon phase can be obtained when the content of P is 0.06%,where the average size of primary silicon phase is decreased from 122μm to 25μm.However,with the addition of 0.09% P,the primary silicon in the alloy can be coarsened.The complex modification of P-La can further improve the refining effect of primary silicon.The optimal refinement on eutectic silicon in the alloy can be observed when the content of La is0.9%,while with La of 1.2%,over-modification effects can be observed.

关 键 词：过共晶铝硅合金 P、La变质 初生SI 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG113.12[金属学及工艺—金属材料]