Study On Microstructures And Mechanical Properties Of5754Aluminum Alloy Sheets By Electromagnetic Roll-casting

5754aluminum alloy sheets have good corrosion resistance, fabrication property and welding performance. It is widely used in the fields of shipping, automobile, aerospace and so on. At present, most of the sheets are produced by the method of casting-rolling. Because of the disadvantages of long process flow and big equipment investment, the method of casting-rolling is not the ideal production process. One of the most economic method of productions is continuous roll-casting. That have advantages of energy conservation, environmental protection, small investment. And with the development of electromagnetic roll-casting on the basis of traditional roll-casting, there are more advantages that traditional roll-casting can’t reach. So it is necessary to study on technology of electromagnetic roll-casting of5754Aluminum Alloy.In this paper,5754aluminum alloy roll-casting sheets were fabricated under the condition of electromagnetic field. The effect of electromagnetic on microstructure and mechanical properties, and the effect of annealing treatment on segregation were analysed. A series of results were obtained as follows:(1)The microstructures of traditional roll-casting sheets were composed of surface layer fine grain zone, edge columnar zone and middle layer, Middle layer was mainly made of equiaxed grains, coarse columnar grains and fine dendrite. The microstructures of lower surface layer were finer than that of upper surface layer.(2) Under the condition of static magnetic field, columnar grains in middle layer decreased and formed dendrite that small; Under the condition of oscillation field, middle layer was mainly made of equiaxed grains and small dendrite, columnar grains almost disappeared.(3) Electromagnetic field could boost the content of alloy element effectively. Static magnetic field was helpful to narrow segregation to be a line. Under oscillation field, bulk and line almost disappear. There was a little spots or fritters in grain boundaries. Segregation could be improved greatly.(4) All of traditional roll-casting sheets and static magnetic field roll-casting sheets and oscillation field roll-casting sheets could improve microstructures after annealing treatment, especially segregation in oscillation field roll-casting sheets after annealing almost disappeared.(5)Electromagnetic roll-casting helped increase the mechanical properties of5754aluminum alloy sheets. The tensile strength of sheet was221.7MPa under traditional roll-casting,233.3MPa under Static magnetic roll-casting,255MPa under oscillation roll-casting.The elongations were almost28%.