2018 Volume 59 Issue 687 Pages 59-63
A processing technology for microholes in sheet metal is required for small electronic devices such as micropumps. Recently, hole processing by electromagnetic piercing has been considered. The flat-plate one-turn coil we use can generate high electromagnetic power, because a strong magnetic field of high frequency can be formed in a narrow linear region. In this report, the results of many simultaneous electromagnetic piercing experiments for different diameters (dh ) and different thicknesses (τ) of A1050-H24 are presented. The minimum energy of piercing (Wp ) and the characteristics of deformation are determined from the results. The relationship between Wp and dh /τ is indicated by one curve. A negligible amount of burr after piercing is observed, but the width of shear droop was 80% of the thickness. A method to determine the maximum magnetic pressure at piercing (Pm ) from the maximum current Im at Wp is described. Pm and Wp exhibit the same tendency with respect to dh . As mentioned above, the results are discussed with respected to both electrical and mechanical engineering.