Aug 03, 2020
Features of laser deep penetration welding:
1) Large depth-width ratio. The molten metal is formed around the cylindrical high temperature vapor cavity and extends to the workpiece, and the weld becomes deep and narrow.
2) Minimum heat input. Because the temperature in the small hole is very high, the melting process takes place extremely fast, the heat input to the workpiece is very low, and the thermal deformation and heat affected zone are small.
3) High density. Because the small holes filled with high-temperature steam are conducive to the stirring of the weld pool and the escape of gas, resulting in the formation of a porous weld. And it is conducive to cooling after welding, making the weld structure finer.
4) Strengthen the weld. The incandescent heat source can reduce the impurity content, and the welding process does not require electrodes or filler wires, and the melting zone is less polluted, making the weld strength and toughness even more than the parent metal.
5) Precise control. Because the focused light spot is small, the weld can be positioned with high precision. The laser output has no "inertia", it can be stopped and restarted at high speed, and complex workpieces can be welded with CNC beam movement technology.
6) Non-contact welding process. Because the energy comes from the photon beam and there is no physical contact with the workpiece, no external force is applied to the workpiece. In addition, the magnetic field and air have no effect on the laser.
Advantages of laser deep penetration welding:
1) Since the focused laser has a much higher power density than conventional methods, the welding speed is fast, the heat-affected zone and deformation are small, and it can also weld difficult-to-weld materials such as titanium.
2) Because the beam is easy to transmit and control, there is no need to change the welding gun and nozzle frequently, and there is no vacuum required for electron beam welding, which significantly reduces the downtime and auxiliary time, so the production efficiency is higher.
3) Due to the purification effect and high cooling rate, the weld seam has high strength, toughness and overall performance.
4) Due to the low average heat input and high processing accuracy, reprocessing costs can be reduced; laser welding operation costs are lower, which can reduce workpiece processing costs.
5) Effective control of beam intensity and fine positioning, easy to realize automatic operation.
Disadvantages of laser deep penetration welding:
1) The welding depth is limited.
2) High requirements for workpiece assembly.
3) High investment in laser system