STUDY OF FIBRE LASER MACHINING OF C45 STEEL: INFLUENCE OF PROCESS PARAMETERS ON MATERIAL REMOVAL RATE AND ROUGHNESS

Aim of the work is to investigate the influence of the process parameters on the material removal rate (MRR) and on the surface roughness in engraving operation by using C45 carbon steel and a Q-Switched 20 W Yb:YAG fibre laser with the fundamental wavelength λ = 1070 nm. The examined parameters were: the pulse frequency, the beam speed, the distance between the linear patterns of two consecutive laser scans, the number of replications of the geometric pattern, and the scanning strategy (only horizontal lines or both horizontal and vertical lines). Experimental results have shown that the Yb:YAG fibre laser can be successfully used to machine C45 steel, obtaining three-dimensional engraved geometries with MRR and roughness strictly depending on the process parameters