Power density of laser processing is the most critical parameters

Power density of laser processing is the most critical parameters. The higher power density, in the microsecond time range, the surface can be heated to the boiling point, resulting in a large number of vaporization. laser pointer has its specific features.
Therefore, high power density for the material removal process, such as drilling, cutting, carving favorable. For lower power density, the surface temperature reaches the boiling point to go through a few milliseconds, before vaporization at the surface, the bottom to the melting point, easy to melt to form a good solder. Therefore, the conduction laser welding, the power density in the range of 104 ~ 106W/CM2. 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. laser pointer is also called mini-laser pointers.
In a laser pulse period, the volatility of the metal reflectivity. 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. Defocus amount of the welding quality. 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. laser pointer is the best sellers among the same series of products.
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. 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 pointer gains in a lot of popularity.