Microstructure of aluminum/copper clad composite fabricated by casting-cold extrusion forming

Abstract

An aluminum/copper clad composite was fabricated by the casting-cold extrusion forming technology and the microstructures of the products were observed and analyzed. It is found that aluminum grains at the interface are refined in the radial profiles of cone-shaped deformation zone, but the grains in the center maintain the original state and the grain size is non-uniform. A clear boundary presents between the refined area and center area. In contrast, the copper grains in the radial profiles have been significantly refined. In the center area of the copper, the grains are bigger than those at the boundary. On the surface of the deformable body, the grain size is the smallest, but with irregular grain morphology. After the product is entirely extruded, all the copper and aluminum grains are refined with small and uniform morphology. In the center area, the average diameter of aluminum grains is smaller than 5 μm, and the copper grain on the surface is about 10 μm. At the interface, the grain size is very small, with a good combination of copper and aluminum. The thickness of interface is in the range of 10–15 μm. Energy spectrum analysis shows that CuAl₃ phase presents at the interface.

Keywords

aluminum/copper clad composite / casting / cold extrusion / microstructure

References

[1] KangC. G., JungY. J., KwonH. C.. Finite element simulation of die design for extrusion process of Al/Cu composite and its experimental investigation [J]. Journal of Materials Processing Technology, 2002, 124(1/2): 49-56

[2] ChenZ. C., IkedaK.. Fabrication of composite pipes by multi-billet extrusion technique [J]. Journal of Materials Processing Technology, 2003, 137(1/2/3): 10-16

[3] LeeJ. S., SonH. T., OhI. H.. Fabrication and characterization of Ti-Cu clad materials by indirect extrusion [J]. Journal of Materials Processing Technology, 2007, 187/188(15): 723-729

[4] XuS., ZhaoG., RenG., MaX.. Numerical simulation and experimental investigation of pure copper deformation behavior for equal channel angular pressing/extrusion process [J]. Computational Materials Science, 2008, 44(2): 247-252

[5] RheeK. Y., HanW. Y., ParkH. J., KimS. S.. Fabrication of aluminum/copper clad composite using hot hydrostatic extrusion process and its material characteristics [J]. Materials Science and Engineering A, 2004, 384(1/2): 70-76

[6] ParkH. J., NaK. H., ChoN. S., LeeY. S.. Hydrostatic extrusion of copper-clad aluminum rod [J]. Journal of Korean Society, Technical Plasticity, 1994, 4(2): 123-130

[7] EivaniA. R., TaheriK. A.. A new method for producing bimetallic rods [J]. Materials Letters, 2007, 61(4): 4110-4113

[8] LuoJ.-t., XuY., ZhaoS.-jing.. Cold extrusion forming of copper/aluminum clad composite [J]. International Journal of Applied Mechanics and Materials, 2009, 16/17/18/19: 441-444

[9] ZaoG. Q., WangG. C., RamanaV.. Die cavity design of near flashless forging process using FEM-based backward simulation [J]. Journal of Materials Processing Technology, 2002, 121(2/3): 173-181

[10] NarayaasamyR., RameshT., PandeyK. S.. Some aspects on strain hardening behaviour in three dimensions of aluminium-iron powder metallurgy composite during cold upsetting [J]. Materials & Design, 2006, 27(8): 279-286

[11] XuY., LuoJ.-t., JiaJ.-bo.. Study on the fabrication of aluminum/copper clad composite by low-pressure compression casting-cold extrusion technology [J]. China Mechanical Engineering, 2009, 20(22): 2755-2758