Publish in OALib Journal
APC: Only $99
Magnetic pulse welding process, one of high speed welding processes, uses electromagnetic force from discharged current through a working coil which develops a repulsive force between the induced currents flowing parallel and in the opposite direction in the pipe to be welded. For achieving the successful weldment and using this process, the design of working coil is the most important factor, because working coil has to generate a high-intensity magnetic field on the surface of the workpiece during the process. Therefore, the objective of this study is to analyze the distribution of electromagnetic force of square working coil for magnetic pulse welding. For this, FE-model has been developed to analyze the distribution of electromagnetic force; after that, distribution of electromagnetic force, results of numerical analysis and experimental results for verifying the developed FE-model were compared. A 3-dimensional electromagnetic FE-model has been developed using a general commercial computer program, ANSYS/EMAG code. The shape and material of square working coil were decided through literature surveys. For the experiment, an MPW equipment W-MPW manufactured by WELDMATE Co., Ltd. was employed
Li2MnSiO4 with different crystal structure was synthesized by solid state reaction method. Their crystal structure and electrochemical properties have been characterized by X-ray diffraction and charge-discharge test. The material prepared at 900oC in N2 atmosphere had γ-phase and its crystal structure changed to β-phase by post-heating at 400oC in air after 900oC sintering. In electrochemical measurement, two materials (γ- and β-phase) showed ~3 and ~45mAh/g, respectively. The different capacities of these two materials might be due to the change of crystal structure.