The Influence of Contour Form Geometric Features and the Number of Cutting Passes on the Surface Quality Characteristics and Critical Points of Cutting Tools Fabricated by Wire Electrical Discharge Machining (WEDM).

Abstract

Since one of the effective methods for producing the form-cutting tools used in the form-turning process involves utilizing a wire cut machine, the effect of the geometric characteristics of the form contour on reducing the negative effects of the recast layer was investigated in this research. The basic assumption of the components for each type of profile form is based on a combination of four modes, i.e., concave arc, convex arc, flat surface, and oblique surface. Based on this, samples were fabricated as cutting tools with three different radii: a convex arc, a concave arc, and a flat surface. During the wire electrical discharge machining (WEDM) operation, one-pass mode was used to create a rough surface, two passes resulted in a semi-finished surface, and three passes resulted in a finished surface. Furthermore, the difference between the surface quality of the recast layer in the two areas above the workpiece or the wire entry point and the bottom area of the workpiece or the wire exit point was studied. Finally, the effect of the direction, size of the curvature and the number of passes in the electric discharge process of the wire on the recast layer was shown, and it was observed that with the increase in the number of passes in WEDM, the thickness of the recast layer was reduced, along with the uniformity of the cutting contour section in the areas close to the cutting region. The entry of the wire was greater than that in the areas near the exit of the wire.