Response surface methodology-based optimization of parameters and cutting quality of 22MnB5 plates by UV picosecond laser layered cutting

Picosecond laser processing technology provides an extremely important and flexible platform for advanced precision manufacturing. Whereas conventional laser cutting of metal plates produces a deep heat affected zone and poor cutting surface roughness. This study investigated the influence of the main process parameters of UV picosecond laser cutting on the cutting quality of 22MnB5 plates. The cut surface roughness, kerf microhardness, kerf microstructure changes, and mechanical properties were evaluated. The experimental results showed that the cut surface roughness of 22MnB5 plate with Ra 0.04 μm, the kerf microhardness with 99.6 % of that of the original plate, the tensile strength with 655.04 MPa, and the strain with 20.91 % obtained after UV picosecond laser processing. The reduction of roughness in the lower part of the cut and the enrichment of the subgrain layer results in superior mechanical properties of the material, and the laser parameters are the important influences on the roughness of the cutting surface and the subgrain layer. This study provides valuable insights into the cutting of millimeter-sized metal sheets with picosecond pulsed laser.