Experimental Research On Electromagnetically Assisted Bending Of Aluminum Sheet

As the development of the light weight of the automobile, aluminum alloys are used in automobile industry. Springback is the main defect during bending forming. It is caused by the elastic recovery of bent area after unloading. It influences the precision of the bending workpiece and the manufacturing efficiency. The traditional bending methods are not very effective to remove the springback of aluminum alloys, electromagnetic forming (EMF) is a high velocity forming technique, this can accelerate the sheet to velocities on the order of 200 m·s^-1 over a distance of a few millimeters. This high velocity forming can be quite beneficial. It can improve formability and strain distribution, reduce the springback of the aluminum alloys.The velocity distribution within the sheet metal during electromagnetic forming significantly influences the result. The forming of the workpiece is controlled by the distribution of the EM pressure, while the spatial distribution of forming pressure in electromagnetic forming can be controlled by the configuration of the coil. It is important that the EM pressure distribution is appropriate for the part that one would wish to form when designing the coil. Uniform press actuators are used in electromagnetic bending and V-sizing. The press distribution of a flat rectangular spiral coil is measured by experimental method, and it is used in U-sizing.In this paper, it mainly studies the electromagnetic bending and sizing of 1060 aluminum sheet. The factors of influencing the forming quality in electromagnetic bending are investigated and how dose some parameters influence springback are discussed too. For electromagnetic bending, the width and length of the free flat have a proper range, if the dimension exceeds this range, the sheet will not flat. The position of bending line affects the forming quality directly, the material of bent area need some shearing and enough bending press, if the bending press is too small, the sheet can't hit the die, and if the shearing press is too large, the workpiece will be cut off, so the bending line should locate between two turns of the coil. With increasing of electromagnetic energy, the springback is reduced and completely removed. Offered the same electromagnetic energy, with increasing of thickness, the springback is more obvious. For electromagnetic sizing, with increasing of electromagnetic energy, the springback is reduced and completely removed, thicker sheet needs more electromagnetic energy to remove the springback. Width dose not influence springback in V-workpiece sizing, but it influences U-workpiece, because of their different coils. Sizing the workoiece several times after lower electromagnetic energy, springback can be reduced and completely removed.