Effect of Properties of Aluminum Alloy Flyer Plate on Formation of Welded Area by Magnetic Pulse Welding of Aluminum and Copper

Magnetic pulse welding of aluminum and copper was performed by changing of type of aluminum alloy used as a flyer plate. Welding experiments showed that weldable charging energy-gap condition differed depending on the aluminum alloy type. Finite element method analysis of collision of aluminum flyer plate and copper parent plate indicated that when a relatively low-strength aluminum alloy was used for the flyer plate, the tip of the flyer plate was rounded and deformed by electromagnetic force. When the high-strength aluminum alloy was used for the flyer plate, the tip of the flyer plate collided with the copper parent plate while remaining flat. The collision velocity and collision angle depended on electrical resistance and tensile strength, respectively. Smooth particle hydrodynamic analysis revealed that the pressure on the order of GPa above Hugoniot elastic limit was generated at the welding interface. Regardless of the aluminum alloy used for the flyer plate, the pressure at welding interface exceeded the Hugoniot elastic limit, and a region above the melting point at high pressure was observed within a few µm from the welding interface at weldable condition.