Mathematical and experimental modeling of plasma channel radius in alternating magnetic field assisted electric discharge machining process

Today, the use of ceramics and hard alloys in advanced industries has led to the creation of new methods such as electric discharge machining in order to reduce the disadvantages of traditional methods of chipping these materials. In turn, these methods also have defects, such as the quality of the machining surface, which in this paper has been tried to solve some of them by using an external alternating magnetic field and conducting practical tests on Inconel 718 hard alloy. In this paper, a Helmholtz coil is proposed to create an external magnetic field using an alternating current around the area of the electric discharge process. In the traditional and proposed method, the radius of the plasma channel is modeled mathematically and numerically, and experimental tests are defined to validate the theoretical results. Comparison of surface uniformity (morphology) and surface roughness (Ra) are considered as effective parameters between the traditional method and the proposed method. The plasma channel is assumed to be cylindrical. A roughness meter is used to control surface roughness. The results of mathematical-numerical modeling show a 10% reduction in the diameter of the plasma channel. According to the obtained results, the amount of surface roughness (Ra) has decreased in fixed times. The basis of validation of the proposed method is to compare the output parameters of machining surface quality in practical tests.