Methods for processing wire EDM cutting

　　The investigation concluded that, with the advancement of new technologies, materials, and processes in the global mold‑design industry, extensive research into high‑strength, high‑hardness, and high‑toughness mold materials can significantly enhance the wear resistance of China’s molds, thereby extending their service life—a benefit that is highly advantageous for enterprises. However, this also poses challenges for the post‑processing of leftover parts from wire EDM operations. Properly addressing the machining issues of these residual components is essential to ensure their surface quality and dimensional accuracy.

　　Especially in plastic mold manufacturing, maintaining high dimensional accuracy during the production of precision multi‑station progressive dies directly affects assembly accuracy, part precision, and die life. Because these workpieces require extremely high machining accuracy, even the slightest oversight during the process can lead to scrap, thereby negatively impacting mold design and manufacturing costs as well as the management of the machining cycle. For small workpieces that are hard, highly precise, complex, and feature uneven machined surfaces, it is particularly important to employ multi‑cutting machining methods to handle the remaining material‑removal operations.

　　 The punch plays a crucial role in the die; its design geometry, dimensional accuracy, and material hardness directly affect the die’s blanking quality, service life, and the precision of the stamped parts. In actual production, residual stresses within the workpiece blanks can cause deformation, while thermal stresses arising during part removal may also lead to distortion. When machining threaded holes, it is advisable to perform closed‑path wire EDM first, thereby minimizing deformation that can result from open‑path cutting. If, due to limitations in the blank dimensions, closed‑path wire EDM is not feasible, for square‑section blanks care should be taken during programming to select an optimal cutting path.

　　The cutting process should be designed to ensure that, throughout machining, the workpiece remains aligned with the fixture within a common coordinate system, thereby minimizing the effects of stress‑induced deformation. With the fixture mounted at the left end, the punch initiates the cut from the left side of the jig and proceeds in a counter‑clockwise direction, dividing the entire blank into two sections along the cutting path. However, because the material connecting the left and right sides of the blank can be removed relatively easily, the right side of the blank gradually becomes detached from the fixture, losing its ability to effectively counteract internal residual stresses and deformations; consequently, the workpiece also undergoes deformation.

　　When machining in the clockwise direction, the workpiece should be positioned to the left of the blank, close to the clamping device. During most cutting operations, both the workpiece and the clamp remain within the same coordinate system, ensuring excellent rigidity and minimizing stress‑induced deformation. In general, the cutting segments in the overall machining program should be separated from the clamped portion of the workpiece, with a well‑planned wire‑cutting path that keeps the pause point near the blank’s clamping end. This type of wire‑cut EDM machine is well suited for producing complex‑shaped molds as well as components such as single gears, splines, and narrow slots with sharp corners, offering advantages like high speed and short cycle times, making it highly popular in practice.

　　In high-speed wire EDM machines, molybdenum wire is the primary choice for the electrode wire. The wire speed typically ranges from 8 to 12 meters per second, and the process employs a reciprocating, double‑pass cycle. During machining, wire breakage is a common issue. If several wires break repeatedly during wire‑cutting operations, it not only results in economic losses for the enterprise but also creates significant challenges in reeling in the wire—wasting time and leaving visible break marks on the workpiece, which degrade product quality and, in severe cases, lead to scrap.