Electrical discharge machining (EDM) is used for machining complex cavities, narrow grooves, ribs, and corner clearing in plastic molds, die-casting molds, and forging molds. Taking the machining of complex reflective grooves in automotive headlight molds as an example, the mold material is hardened mold steel, and the cavity contains hundreds of ribs, each 0.3mm wide and 8mm deep, requiring clear corners. A comb-shaped combination electrode made of high-purity graphite is used. Two processes, roughing and finishing, are planned. Roughing uses a large current to quickly remove most of the material. Finishing uses a new electrode and low current and short pulse width parameters to achieve a surface finish with a side surface area Ra of less than 0.4μm and clear corners. Process control is achieved through a high-precision CNC EDM machine and a timed workpiece cleaning fluid filter, ultimately ensuring consistent dimensions of all ribs, good side perpendicularity, and clear corners. Commonly used electrode materials include copper, graphite, and copper-tungsten/silver-tungsten alloys, suitable for cemented carbide molds or precision micro-machining where electrode wear is extremely critical. Electrical discharge machining (EDM) can also be used to "grow" metal within damaged mold cavities, or to repair damaged parts by removing them through electrical discharge and then inserting inserts.
Modern mold manufacturing processes are undergoing profound changes. The deep application of integrated CAD/CAM/CAE technology, AI simulation, 3D printing, and other digital tools has completely transformed traditional design and manufacturing processes. AI algorithms can optimize mold structures, predict forming defects, significantly shorten design cycles, and reduce trial-and-error costs; 3D printing technology has broken through the processing limitations of complex mold structures, enabling rapid prototyping and shortening delivery cycles. Intelligent manufacturing requires interconnected and collaborative operation between molding dies, equipment, and management systems.
