Laser welding and laser soldering

Laser welding and laser soldering

The laser beam provides a variety of ways to join metals: it can join workpieces at the surface or produce deep welds. It can be combined with conventional welding methods and, additionally, be used for soldering.
Laserschweißen von Dickblech.
Even when seam welding with continuous laser beams, the heat-affected zones and the complete heating of the component are still considerably less than with arc or plasma welding. The supply of energy can be well monitored, regulated and maintained or precisely controlled.

Materials with a high melting point as well as high heat conductivity can be welded using a laser. Due to the small amount of molten material and the short, controllable melting period, some materials can be combined, which otherwise could not be welded. Filler materials can be used, if needed. Even when seam welding with continuous laser beams, the heat-affected zones and the complete heating of the component are still considerably less than with arc or plasma welding. The supply of energy can be well monitored, regulated and maintained or precisely controlled.
In soldering, the mating parts are joined by a filler material, or solder. The surface of the solder seam is smooth and clean, forming a nicely curved transition to the workpiece. Since solder seams do not require finishing, they are often used in the automotive industry for making body parts such as trunk lids or car roofs.

Heat conduction welding

Heat conduction welding

In heat conduction welding, the laser beam melts the mating parts along a common joint. The molten materials flow together and solidify to form the weld.
In heat conduction welding, the surface is melted.

Heat conduction welding is used to join thin-wall parts. One example of this are corner welds on the visible surfaces of device housings. Other applications can be found in electronics. The laser produces a smooth, rounded seam that does not require any extra grinding or finishing. Pulsed or continuous wave solid-state lasers are used in such applications. In heat conduction welding, energy is coupled into the workpiece solely through heat conduction. For this reason, the weld depth ranges from only a few tenths of a millimeter to 1 millimeter. The heat conductivity of the material limits the maximum weld depth. The width of the weld is always greater than its depth. If the heat is not able to dissipate quickly enough, the processing temperature rises above the vaporization temperature. Metal vapor forms, the welding depth increases sharply, and the process turns into deep penetration welding.