Fabrication of microcutting tools by pulsed electrochemical machining (PECM)

Abstract Micromachining techniques are facing new challenges as the global demand for miniature products has rapidly increased. Among these techniques, micromilling is one of the most important processes for producing complex parts with high surface quality. The performance, precision, and cost-efficiency of micromilling operations are heavily influenced by the microcutting tools utilized and thus directly affected by their manufacturing process. Mechanical material removal techniques, such as grinding, generate high specific machining forces, particularly for microtools, which can lead to substantial production waste. Additionally, due to the fragile and brittle nature of microtools, current manufacturing processes face productivity challenges, including tool wear, difficulty in machining undercuts, and suboptimal surface finishes due to grinding marks. These limitations result into increased costs and compromised product quality. To address these challenges, new manufacturing techniques that minimize mechanical and thermal stresses are being investigated to produce high quality, cost-effective microcutting tools. This study investigates the use of pulsed electrochemical machining (PECM) for fabricating two-flute micro end mills with a cutting diameter d = 1 mm. PECM offers significant advantages, including the elimination of mechanical and thermal stresses. It also has the possibility to machine multiple tools simultaneously, greatly increasing process productivity. Micromilling cutters of diameter d = 1 mm, made of ASP 2030 tool steel, were successfully fabricated using PECM process. The resulting microtools achieved a mean cutting edge radius of r = 2.62 ± 0.23 μm for the minor cutting edge and r = 3.92 ± 1.30 μm for the major cutting edge, demonstrating the process’s capability for precision and efficiency.