more accurately ad flexibly

Laser pulse shape in laser welding is an important issue, especially for welding thin is more important. When high-intensity laser beam shot to the surface, the metal surface will be 60 ~ 98% of the laser energy reflection is lost, and the reflectivity change with surface temperature. In a laser pulse period, the volatility of the metal reflectivity.  laser pointer will be more convenient for the user to locate the target more accurately ad flexibly.
Pulse width is one of the important parameters of laser welding, it is both material removal and material different from the melting of the important parameters, determining the cost of processing equipment and the volume of key parameters. Laser welding usually requires a certain issue from one focus of the laser power density at the center spot is too high, to evaporate into the hole. Leave the laser focus of the plane, the power density distribution is relatively uniform. Defocus in two ways: positive and negative defocus defocus. Focal plane at the top of the workpiece is out of focus, and vice versa for negative defocus. Geometrical optics theory, when the issue from an equal positive and negative, corresponding to approximately the same power density on the plane, but in fact obtained pool of different shapes. Negative defocus, the availability of greater penetration, which is the formation of the pool. Experiments show that the laser heating 50 ~ 200us material begins to melt, the formation of liquid metal and the emergence of sub-vaporization asked to form a city-pressure steam, and high speed jet, a dazzling white light. At the same time, high concentrations of vapor to liquid metal movement to the pool edge, the formation of sag in the center pool. When the negative defocus, the material internal surface area is higher power density, easy to form a stronger melting, vaporization, so that light passes to the deeper material. The sensitivity of the part of laser pointer will not reduce as time goes by.
So in practice, when required penetration depth is large, the use of negative defocus; welding thin materials, it is appropriate is out of focus. Laser welding processes. Between film and sheet welding. Including welding, side welding, fusion welding center through the center hole 4 kinds of fusion welding process method. Wire and wire welding. Including wire and wire welding, cross welding, lap welding parallel, T-4 kinds of welding process method. Wire welding with the lumped elements.