连续铸造法制备3003／4004铝合金复层圆铸坯

CONTINUOUS CASTING OF THE CLADDING 3003/4004 ALUMINUM ALLOY CIRCULAR INGOT

采用直接水冷连续铸造法制备了3003/4004铝合金复层圆铸坯,使用OM,SEM和EPAM对复层铸锭界面凝固组织及元素分布进行了系统的检测,并对3003/4004铝合金复层铸坯进行拉伸实验,分析其界面结合强度.OM结果表明,直接水冷连续铸造法所制备的3003/4004铝合金复层圆铸坯界面清晰,无气孔、夹杂等缺陷,整个铸锭断面大部分为等轴晶组织.利用EPAM对结合界面进行线扫描分析,结果表明,3003和4004铝合金溶质元素间发生了相互扩散,形成厚度约为30μm的扩散层.复层铸坯拉伸实验结果表明,3个拉伸试样都在强度较低的3003铝合金一侧断裂,试样抗拉强度为107.7 MPa,说明复层铸坯界面结合强度高于3003铝合金抗拉强度,界面结合牢固.

Cladding metals have been widely applied to many fields because they have many excellent physical, chemical and mechanical properties that can not be obtained from the single metals. There are many conventional processes for manufacturing cladding metals, for example roll bonding, diffusion bonding, explosive welding, extrusion cladding and casting cladding. Among these processes, continuous casting is an ideal process to prepare cladding metals which has the advantages of high production efficiency, low production cost and good interface bonding. This process can make two metals contact directly by the ways of one liquid-one liquid, one liquid-one solid or one liquid-one semi- solid and then the good metallurgical bonding can be obtained. So, this process is extensively studied by researchers engaging in material processing. The process of the direct water-cooled continuous casting to fabricate cladding 3003/4004 aluminum alloy circular ingot is researched in this paper. The 3003 aluminum alloy has excellent corrosion resistance, low strength and high melting point, while the 4004 aluminum alloy has poor corrosion resistance, high strength and low melting point. The cladding 3003/4004 aluminum alloy material can combine the advantages of two metals and can be widely used in many fields, especially in car engine and air conditioning heat sink. To obtain the good interface bonding, a special inner mold with the single-side cooling capability was applied in this process. By the special inner mold, the two alloys can make the contact of one liquid-one solid or one liquid-one semi solid on the interface. The solidification structure and elemental distribution near tile interface of cladding ingot were systematically detected by OM, SEM and EPAM. Tensile test was carried out to evaluate the interface bonding strength. The OM results indicated that the interface of cladding 3003/4004 aluminum alloy ingot was clear without gas holes and slag inclusion. Most grains were equiaxed in the cross-section of cladding 3003/4004 alumimlm alloy circular ingot. The EPAM results suggested that the interdiffusion of alloy elements in 3003 and 4004 alloy occurred and there was an about 30 μm wide diffusion layer near the interface. The entire tensile specimen fractured in the sides of 3003 alloy with the average ultimate tensile strength of 107.7 MPa, indicating that the interface bonding strength of cladding ingot was higher than the ultimate tensile strength of 3003 alloy and the good metallurgical bonding near the interface was obtained by this process.