These characteristics allow narrower cuts, which in turn enhance cutting speeds because there is less material to be cut. As a result, diffusion-cooled CO2 slab lasers are especially suitable for thin sheet metal processing.
Cutting speeds on mild steel attained with a 2.5-kW CO2 slab laser are very comparable to the results obtained with a conventional fast-axial-flow CO2 laser with 4-kW output power. It is only when sheet metal is thicker than 10 mm that the differences in speed become significant.
In laser fusion cutting of aluminum, the effect of the higher beam quality becomes more evident. In the thickness range below 2 mm, slab laser speeds exceed comparative values obtained with flow lasers. Up to a thickness of 4 mm, both beam sources achieve similar results. When cutting thicker metal sheets, however, the higher wattage flow laser beam source has an apparent advantage.
Similar effects are observed when cutting stainless steel. In this case, however, higher-power lasers show benefits at sheet metal thicknesses of more than 2 mm. At sheet metal thickness range around 1 mm, however, the lasers with maximum beam quality attain higher speeds compared to conventional beam sources, provided that the system periphery is adjusted accordingly
Another important factor to be considered in conjunction with the operating expenses is the laser design. For instance, diffusion-cooled CO2 slab lasers have a simple layout involving only two metallic mirrors. The diffusion cooling principle eliminates the need for turbines and blowers for gas circulation, giving rise to an almost wear-resistant laser.
Owing to the negligible gas consumption of diffusion-cooled CO2 slab lasers, the premix gas bottle integrated into the laser head allows more than a year of continuous operation. After this period, the bottle is exchanged for a new one. Thus, no external laser gas supply is needed.