复合工艺对半固态A356铝合金浆料组织的影响  

Effect of compound process on semi-solid slurry of A356 aluminum alloys

作　　者：汤国兴[1] 毛卫民[1] 刘永峰[1] 

机构地区：[1]北京科技大学材料科学与工程学院

出　　处：《材料研究学报》2008年第2期167-170,共4页Chinese Journal of Materials Research

基　　金：国家“863”高技术研究发展项目2006AA03Z115;国家重点基础研究规划项目2006CB605203;国家自然科学基金50374012~~

摘　　要：用低过热度浇注和弱行波电磁搅拌工艺制备A356铝合金半固态浆料,研究了浇注温度和搅拌功率等复合工艺参数对A356铝合金的半固态浆料的影响.结果表明,这个复合工艺促使初生α-Al几乎在整个熔体区域形核,增加了初生α-Al同时形核的位置和数量,在合金凝固的初期形成足够多的晶核,从而在合金熔体中形成球形或近球形的组织.在浇注温度和浇注功率分别为630℃和1.2 kW条件下可以制备出球状初生α-Al晶粒的A356铝合金半固态浆料.与单纯低过热度浇注的A356铝合金试样相比,在弱行波电磁搅拌条件下,适当提高浇注温度也可获得理想的球状A356铝合金浆料,同时可简化浇注工艺.The semi-solid slurry of A356 aluminum alloy was prepared by a method of low superheat pouring and weak traveling-wave electromagnetic stirring and the effects of pouring temperature, stirring power and stirring time on the semi-solid slurry were investigated. The results show that the nucleation sites for primary α-Al quickly spread throughout the whole melt region and the number of nuclei can be increased at the same time. So the grain density is high enough in the early stage of solidification and the spherical primary α-Al grains are formed in the end. When a spherical semi-solid A356 aluminum alloy slurry is manufactured by this method, the proper pouring temperature, stirring power and stirring time should be 630 ℃ 1.2 kW and about 6s respectively. On the condition of weak traveling-wave electromagnetic stirring, the pouring temperature can be suitably raised and the same ideal spherical microstructure, which is usually gotten only from a lower pouring temperature without stirring, can also be obtained. Therefore the pouring operation is simple and convenient.

关 键 词：金属材料 半固态 低过热度浇注 行波搅拌 A356铝合金 

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