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High Energy Rate Forming (HERF)
Published in Gary F. Benedict, Nontraditional Manufacturing Processes, 2017
Electromagnetic forming is a process used for forming electrically conductive workpieces by electromagnetic pressure. The workpiece is placed in the proximity of a pulsed magnetic field that is created by an electrically driven magnetic coil. During the electrical pulse, eddy currents created within the part act to resist the force of the coil’s magnetic flux. The resulting force between the magnetic field and the eddy currents deforms the part, rapidly pushing it into the die. Forces of approximately 410 MPa (60,000 psi) can be achieved with electromagnetic forming.
Electromagnetic attractive forming of aluminum alloy sheets utilizing a low-frequency half-wave current
Published in Materials and Manufacturing Processes, 2022
Shaowei Ouyang, Limeng Du, Quanliang Cao, Liang Li
Electromagnetic forming using pulsed Lorentz forces is a widely-studied high-speed forming technology in the fields of both sheet metal and tube forming.[1–9] In the existing EMF literature, the workpiece and coil are mutually exclusive by repulsive forces, which makes it hard to be used in certain applications. Taking the dent repair of vehicles as an example, an ideal working condition is to remove dents without disassembling the car components through placing the coil outside the car. However, the conventional repulsive EMF could fail because in this case the coil and the dent should attract each other.
Manufacturing methods for metallic bipolar plates for polymer electrolyte membrane fuel cell
Published in Materials and Manufacturing Processes, 2019
Oluwaseun Ayotunde Alo, Iyiola Olatunji Otunniyi, HCvZ Pienaar
Another disadvantage of the electromagnetic forming process is that high currents and voltages resulting in strong magnetic fields can occur during the process. Therefore, significant safety requirements are involved.[155] Also, only a small proportion of the charging energy is used for plastic deformation, leading to poor efficiency.[155,159] A maximum efficiency of 25% in free compression or expansion EMF process has been reported but the efficiency is generally below 10% for other types of forming and as low as 3–4% for sheet metal forming.[155]
Experimental and numerical study on the influence of process parameters in electromagnetic compression of AA6061 tube
Published in Materials and Manufacturing Processes, 2019
Amitabh Shrivastava, Amit Telang, A.K. Jha, Meraj Ahmed
Electromagnetic forming (EMF) is a high speed and high strain rate forming process that offers several advantages in forming and joining of light materials like Al and Mg alloys. Joost[1] reported the application of lightweight materials in automobile and aerospace industries. It offers fuel economy and associated advantages. The process is based on principle of electromagnetic induction. In the process, a transient magnetic field is generated between the coil and the workpiece by passing a sinusoidal–damped pulse current through coil. A fully charged capacitor bank is discharged in a few microseconds. The high–pulse generated current passing through coil creates a transient magnetic field surrounding it, which induces transient eddy current in the nearby placed workpiece. These two primary and secondary currents and their associated magnetic field produce Lorentz force between coil and workpiece leading to plastic deformation of the workpiece. Haiping et al.[2] explained the added benefits of this process over other processes such as improved formability, reduction in wrinkling and springback, high accuracy, and rapid processing cycle. Tak et al.[3] reported improvement in workability using preheating technique in EMF process. There are applications of the process in the field of tubular compression and expansion process. Electromagnetic compression (EMC) is a type of EMF process used for many applications in manufacturing industries like cladding, welding, and crimping. A typical advantage of EMC technique is for joining of similar and/or dissimilar lightweight materials. Optimum design of system can be achieved by controlling the parameters like pulse of discharge current, and workpiece geometry, and coil design. Haiping et al.[2] also studied compression of tube using sequential coupling for EMC by ANSYS software. Various aspects of work have been reported in this area.