February 24, 2021
The stages of laser cutting are beam generation, beam focusing, heating and melting of the working area and beam movement. The final quality of the laser cut that emerges from these stages depends on the following:
Material parameters: The type of material, as well as its shape, thickness and thermal properties, influences the quality of the laser cut. The surface characteristics of the material also impact the cut. Further, the presence of dirt, scale, sand and even paint deflects the gas flow. In addition, the reflectivity of the material also needs to be considered.
Beam parameters: The laser beam’s power, along with its intensity, quality, polarization and wavelength, affects the outcome. When the laser power parameter is set right, it ensures that the material is cut as required, while generating little to no “melt.” Higher the laser power, lower the processing time.
Process parameters: These consist largely of those parameters that can be adjusted to arrive at the required cut quality. These include the focal length and the focal position of the lens, cutting speed, nozzle diameter and/or alignment, the distance from the workpiece, the choice of continuous beam or pulsed beam, and the choice of assist gas and its pressure setting. It must be noted here that an unclean focusing lens can lead to it heating up and being deformed and damaged in extreme cases. Lens deformation shifts the focal position. Thereby, burrs may form, and surface roughness may develop. Exact focus-point positioning of the lens is critical for good results.
As you’ll find in this post, assist gases do a whole lot more than just blow away the build-up accumulated during the laser cutting process. If you are looking to set up your laser-cutting enterprise or to step up your existing operations, explore Pneumatech’s range of nitrogen generators. Or get in touch with us right away.