Copper plate welding with 100 W blue diode laser

A bead on plate weld test was conducted on a thin pure copper plate using a high intensity blue diode laser with an output of 100 W and a beam diameter of 100 μm. Pure copper with a thickness of 50 μm was irradiated with laser beams power at 30,50,97 W, laser intensity at 3.6×105, 6.3×105, 1.24×106 W/cm2. Amount of input energy J/cm2 was controlled by changing laser power and sweeping speed. As a result, when the input energy is the same, the higher laser intensity formed the wider bead. The through bead was observed at laser intensity 1.24×106 W/cm2 at input energy 330 J/cm2, and the bead width was 106 µm, which was a bead having substantially the same width as the beam diameter. Then Two pieces of pure copper having a thickness of 30 µm were lap weld at laser intensity 1.24×106 W/cm2 and an input energy 1900 J/cm 2. Two copper thin plates were joined with a bead width of 215 µm without cross section defects such as pores and cracks.