Theoretical estimation of achievable travel rates in inert-gas fusion cutting with fibre and CO2 lasers

Inert-gas fusion cutting is commonly realised with CO2 lasers. However, it has been demonstrated in recent investigations that the use of fibre lasers offers the potential to improve the process efficiency dramatically. It has been shown in comparative experimental studies that the maximum cutting rates in fibre laser cutting can be much higher than the travel speeds in CO2 laser cutting. Unfortunately, this advantage seems to be currently limited to light and medium sheet metal cutting whereas the travel rates in thick section cutting are of comparable magnitude. This experimental fact is in a good agreement to theoretical estimations of the achievable cutting rates provided that the different absorptivity behaviour of ferrous alloys at the corresponding wavelengths of 1.07 and 10.6 microns of fibre and CO2 laser radiation is taken into account.