Investigation of laser-assisted high-speed precise blanking of metal bars

A laser-assisted high-speed precise blanking method is proposed for metal bars with V-shape notches, which processes annular cracks at the notch bottom by millisecond laser to induce brittle fracture, and then applies 5-10 m/s high-speed load to complete precise blanking on a hydro-pneumatic hammer. The effects of notch geometry, crack depth, and loading speed are investigated on the fracture behavior of steel bars by finite-element simulation and experimental tests. Moreover, the surface quality is investigated by indexes of flatness error and roundness error with confocal microscopy. The results show that the new method effectively inhibits plastic deformation, and significantly reduces the impact force and fracture energy. Moreover, high-precision sections are obtained with a flatness error of 0.6 mm, a roundness error of 2.1%, and plastic bending deformation of 0.4 mm. The new method shows the advantages of high precision and efficiency, and low energy consumption.