Microstructures And Mechanical Properties Of5182Aluminum Alloy Sheets By Electromagnetic Twin-roll Casting

5182aluminum alloy has good corrosion resistance, fabrication property and welding performance. It is widely used in the fields of can-cover, automobile, aerospace and so on. Currently most of the aluminum alloy sheets are produced by cast and rolling method, which has long process flow, big equipment investment and high production cost. Aluminum alloy twin-roll continuous casting technology is the most economical methods of production. That has advantages of energy conservation, environmental protection, small investment and low production cost.In this paper,5182aluminum alloy sheets were fabricated under the condition of electromagnetic field. The solidification feature of roll-casting area of5052aluminum alloy was analyzed. The effect of static magnetic field and electromagnetic oscillation on microstructures of roll-casting area and segregation of alloy elements was researched. The effect of static magnetic field and electromagnetic oscillation on microstructures of sheet and mechanical properties was analyzed. A series of results were obtained as follows:(1) Static magnetic field roll-casting refined microstructures of roll-casting zone, increased intracrystalline content of alloy element, decreased precipitation and shortened the length of crystallization fields. But electromagnetic oscillation roll-casting had better refinement effect and shorter crystallization fields.(2) The microstructures of common roll-casting sheets were composed of surface layer fine grain zone, edge columnar zone and middle layer. Middle layer is mainly made of equiaxed grains, coarse columnar grains and fine mess dendrite. The microstructures of lower surface layer were finer than that of upper surface layer.(3) Due to the influence of static magnetic field, microstructures of middle layer of roll-casting sheets changed. Equiaxed grains increased and grains refined. Columnar grains decreased. Fine mess dendrite increased. Compared with common roll-casting, edge microstructures of sheets obtained by static magnetic field roll-casting refined. Under the condition of oscillating field, middle layer of roll-casting sheets made of equiaxed grains and fine dendrites. Grains obtained under oscillating field were finer than those obtained under static magnetic field.(4) Under common roll-casting, the intracrystalline content of Mg of middle layer of roll-casting sheets was3.50%and the content of edge was1.61%; under static magnetic field roll-casting, the content of middle layer was2.91%and the content of edge was1.99%; under electromagnetic oscillation roll-casting, the content of middle layer was2.60%and the content of edge was2.41%. Electromagnetic oscillation roll-casting virtually eliminated segregation.(5) Electromagnetic field roll-casting helped improve the mechanical properties of51822aluminum alloy sheet after rolling and annealing. The tensile strength of sheet was271.7MPa and the elongation was20.7%under common roll-casting; The tensile strength was281.7MPa and the elongation was22.2%under static magnetic field roll-casting; The tensile strength was290.3MPa and the elongation was26.0%under electromagnetic oscillation roll-casting.