Laser welding machine is a new type of welding method that can weld thin-walled materials and precision parts. The laser welding process uses high-energy laser pulses to locally heat tiny areas of material, and the energy from the laser radiation diffuses into the interior of the material through heat conduction, thereby melting the material into a specific molten pool.
Laser welding machine is also known as fiber laser welding machine and pulsed laser welding machine. Although it is simple to operate, there are still some factors that can affect the quality of laser welding. How to control these factors in the high speed continuous laser welding process within the right range to ensure the welding quality. This article will provide you with some reference.
Quality of laser welding equipment
The beam pattern, output power and stability are the most important aspects of the quality of a laser welding machine. The beam mode is an important indicator of the beam quality. The lower the beam mode order, the better the beam focusing performance. The smaller the spot, the greater the power density and the greater the weld depth and width at the same laser power.
In the optical system, the focusing lens is an important factor in the quality of the weld. The focal length is usually between 127 mm (5 inches) and 200 mm (7.9 inches). Smaller focal lengths help to reduce the diameter of the focusing beam waist spot, but too small a focal length tends to cause weld contamination and spatter.
Workpiece Conditions
Laser welding is the processing of the edges of the workpiece, requiring that the gap between the workpieces should not be too large. General plate butt assembly gap and point butt joint deviation should not be greater than 0.1 mm, the misalignment should not be greater than 0.2 mm. in actual production, laser welding technology can not meet these requirements. In order to obtain good welding results, the allowable amount of butt gap and lap gap should be controlled within 10% of the thickness of the thin plate.
Successful laser welding requires close contact between the welded parts, which requires careful tight fixing of the material to obtain good welding results.
Laser welding parameters
When the welding speed is too high, a stable deep melt welding process cannot be maintained due to the small heat input. In practice, stable deep-fusion welding or stable heat conduction welding should be used according to the penetration requirements of the welded workpiece, and unstable mode welding should be avoided.
In the stable range of deep fusion welding, the higher the laser power, the greater the depth of melting; the higher the welding speed, the shallower the depth of penetration.
The common shielding gas used in laser welding machines is argon or helium. If the welding quality requirements are not high, nitrogen can also be used. Under the same conditions, helium has less tendency to produce plasma than argon, so greater penetration can be obtained. Within a certain range, as the flow of shielding gas increases, the tendency of plasma suppression increases, so the amount of penetration increases, but increases to a certain range tends to stabilize.
In the continuous development of laser technology, the application of laser welding machines to meet the production needs of different fields. In the process of laser welding, in order to obtain a successful welded workpiece, on the one hand, you need to purchase high-quality, highly stable laser welding equipment, and should be regularly maintained to keep the equipment clean. On the other hand, it is necessary to set the correct welding parameters according to the type of workpiece in order to obtain a good welding result.
