Views: 32 Author: Site Editor Publish Time: 12-28-2021 Origin: Site
With the expansion of fiber lasers in the field of industrial processing, the thermal lens effect is inevitable in the application of medium and high power pulsed fiber lasers. The thermal lens effect will affect the stability of laser processing. How to avoid the thermal lens effect? What are the thermal lens effects in laser processing? Leapion laser shares are as follows:
Due to the poor quality of optical components, dirt, damage and other reasons, the absorption rate of the laser increases. After the optical components are irradiated by the laser beam for a long time, the temperature rises and thermal deformation occurs, which in turn causes the refractive index and the refractive index of the transmissive optical components. The reflection direction of the reflective optical element changes. The thermal lens effect will change the focus position of the laser, thereby affecting the application effect.
Since the transmissive optical element has a higher absorption rate of laser light and a greater temperature rise, the thermal lens effect is more obvious.
The higher the power and the processing of high-reflection materials, the faster the thermal expansion of the optical element, and the more obvious the thermal lens; when the thermal lens effect occurs, the thermal expansion of the optical element will increase the focusing ability, the size of the focused spot will decrease, and the focal length and focal depth will become shorter. Phenomenon.
The occurrence of these phenomena will eventually cause the laser processing to be unstable and affect the laser processing effect.
1. Spot welding of metal flakes:
For high-power fiber laser spot welding of metal flakes, the thermal lens effect will cause inconsistent welding spot size, weak welding, and insufficient drawing force.
2. Continuous metal welding:
Continuous light welding metal has a higher reflectivity than cutting. During high-power welding, the thermal lens effect will cause the front part of the welding to be normal, and the rear part of the welding depth is shallow or completely incomplete. Welding aluminum and copper high-reflective materials, the thermal lens effect is more obvious.
1. Stainless steel cutting:
When stainless steel is cut, the thermal lens effect will cause the cutting surface to be inconsistent, more and more dross, and even continuous cutting problems.
2. Carbon steel cutting:
When carbon steel is cut, the thermal lens effect will cause more and more slag at the bottom, and continuous cutting problems.
1. In the production process, in order to avoid the thermal lens effect, check the cleaning condition of the laser output head before installation, whether the lens or crystal is dirty or damaged, if any, clean and replace it;
2. It is necessary to check whether the protective lens, collimating chip set, and focusing lens set of the cutting head are of poor quality, dirty or damaged. If so, clean the lens or replace the good quality lens.
We have already shared the influence of thermal lens effect in laser marking. If you want to know more about professional issues about laser machines, please consult Leapion Laser.
