Numerical simulation and experimentation of a novel micro scale laser high speed punching

Abstract A novel process technology for micro punching of thin sheet metals is presented in this paper. The laser induced shock waves act as the micro punch. The forming speed can be controlled by adjusting the laser energy. Micro holes of 250 μm in diameter were successfully punched on sheet metal of 10 μm in thickness by single pulse, and good edge quality was obtained. The micro die-opening is produced by electrical discharge machining (EDM) using the copper electrode of φ=220 μm. In the experiment, a sacrificial coating is used to generate high-pressure plasma under a laser pulse, so no signs of melting, burning, or ablation were observed on the workpiece. The novel process of micro scale laser high speed punching is also numerically studied. In addition, this method can be used to fabricate noncircular micro holes on thin sheet metals with noncircular micro die-openings. With further development, laser high speed punching may become an important micro punching technology, which is characterized by non-contact, low cost, and high efficiency.