There are many factors that can affect laser cutting quality; the machine, the operator and material can all have a bearing on quality of the cut edge. However, more critical parameters to laser cutting quality are material thickness and material type.
Thickness
The cutting edge quality achievable with laser profiling depends on the type of material and the thickness. As the thickness increases the striations on the cut-edge become more prominent.
Striations are regular lines on the cut-edge where the molten zone meets the cool zone, which lowers the quality of the surfaces produced. The thicker the material, the more pronounced the striations are.
Material Type
Material type can cover a large remit of different factors, the most obvious is the type of metal itself. Different metals possess different properties and so each react differently when being laser cut.
The composition of metals can have a profound effect on the cut edge quality, levels of carbon, manganese, silicon, phosphorus and sulphur can all have a bearing on the surface quality provided by laser cutting. For example, the higher the carbon content in mild steel the harder the cut edge will become.
Material Quality
Laser profiling is more reliant on a consistent surface quality that other cutting methods. The surface finish quality of the sheet can drastically affect the quality of the cut. We recommend that steel should be clean, pickled, rust and oil-free.
Low-grade steels represent a considerable problem for laser cutting. The impurities within these low grades can be highly reactive to the thermal cutting process, especially if using oxygen assisted laser cutting.
Hot rolled steel can also prove to be problematic for laser cutting due to its surface scale. The surface can melt in with the metal, creating a low quality cut finish. If the surface is not smooth and free of imperfections, the laser focus can be altered, affecting the cleanness and quality of the cut.
Laser Power
One way to improve the effects and reduce the appearance of striations of thicker sheets of metal, more powerful laser machines can be used. Using a higher powered laser enables the beam to cut through thicker sheets of metal easier and thus produces a better edge quality compared to less powerful counterparts.
Laser Technology
The recent improvements in fibre-delivered, solid state laser technologies have stimulated competition with the well-established CO2 laser cutting process. Fibre lasers provide considerably faster cutting speeds compared to their CO2 equivalents while maintaining equal cut edge quality, in terms of nominal surface roughness.
Newlaz provide a set of mature retrofitting solutions to upgrade Bystronic and Trumpf CO2 laser cutting machine to fiber laser. It takes less time and you will get big return such as high cutting efficiency, low electricity and gas charges, low maintenance cost.
