Melting and Cavity Growth in the Vicinity of Crack Tips Subjected to Short-Duration Current Pulses

A cutting mechanism map for machining metallic sheets using electric current pulses

“…These two effects work in tandem in a conductor with a pre-existing crack, resulting in removal of the molten material from the crack tip upon application of an electric current. Therefore, the resultant 'sawing effect' leads to formation of a blow-hole at the tip of the pre-existing crack in the conductors [2][3][4][5][6][7][8].…”

“…Herein, authors extended a pre-existing crack in a metallic sheet by generating magnetic-saw effect in it by inducing a varying magnetic field by placing a coil carrying fluctuating current in the close proximity of the work-piece. In addition, Gallo et al [7,8] and Sharma and Kumar [15] provided quantitative relationships between a few of the test parameters, such as electric current, crack length, etc., and the size of the blow-hole formed at the crack tip. These quantitative relationships further help to develop cutting tools using electric pulse loading.…”

“…Since the noncontact manufacturing processes include no tool wear, ability to machine hard-to-cut metals and time efficiency, these new techniques are very promising in modern manufacturing industry, despite their limitation on maximum cutting rate, generation of a heat-affected zone and unsuitability for machining insulators. Therefore, machining a metal sheet or plate by extending a pre-existing cut by applying a pulsed electric current has generated significant interest recently [7,[13][14][15][16][17][18]. However, a systematic study providing details of the effect of cutting conditions of temperature and electric current density, which are the two most important user-selected cutting parameters, on the cut profile is not available.…”