Influence of Process Parameters in Laser Piercing

Abstract

This work addresses the analysis of the influence of process parameters in laser piercing for mild steel, stainless steel, and aluminum thick sheets, carried out by the monitorization of the signal with a photodiode installed coaxially in the cutting head. The sensor captures the infrared or visible signal emitted during the piercing. The relationship between the intensity of the signal and the parameter values was analyzed, distinguishing between soft and fast piercings. The results permit the optimization of the piercing strategy with a reduction of 25% in time and the possibility of establishing a threshold to control the piercing process. This study reveals the importance of knowing parameter dependencies with the process results and highlights the potential of monitorization systems in laser cutting to improve the piercing duration and avoid wasting time during production.

Analysis of Photodiode Monitoring in Laser Cutting

“…IR monitoring signals showed a contrary effect (0.7 V vs. 0.4 V, for 5 and 10 mm). In this case, the measured infrared signal was related to temperature [25], which decreased in the thicker plate as a consequence of heat conduction phenomena, according to the literature [27].…”

“…To analyze the influence of the thickness in the registered signal, two aluminum plates of 5 and 10 mm thickness were cut with N 2 at 5 kW, with the velocity, gas pressure, and focal position specified in Table 1. Comparing VIS monitoring signals, the 10 mm thick plate displayed a higher value than the thinner one (0.6 V vs. 0.15 V), explained as a consequence of more vapor plume formation [25] during the cutting process of the thicker plate, and thus, an increase in VIS signal. IR monitoring signals showed a contrary effect (0.7 V vs. 0.4 V, for 5 and 10 mm).…”

“…This study quantitatively investigated the correlation between the cutting process parameters and monitoring signals, evaluating the results in four different cutting scenarios which implied variations in the assist gas, material, and thickness. The present work focuses on contour cutting because the piercing operation was previously studied [25]. The results aim to contribute to future development of monitoring systems that will allow the correct detection of cutting losses in different working scenarios, even in cases of having too low or too high-intensity monitoring signals as a consequence of variations in material thickness, emissivity, or any other implied process variable.…”

S235JR Metal Malzeme İçin Fiber Lazer Kesim Parametrelerinin Belirlenmesi

“…Kesim parametrelerinden frekansın değişmesinin kesim yüzeyine etkisinin olmadığı görülmüştür. Frekans piercing (delme, patlatma) parametrelerinde, patlatma çaplarının değiştirilmesi için kullanılmaktadır [12].…”