Product Code: ICA11_M102

Micro Processing of Metals using a High Repetition Rate Femtosecond Laser: from Laser Process Parameter Study to Machining Examples
Authors:
J. Schille, University of Applied Sciences Mittweida, University of Manchester; Mittweida Germany
L. Schneider, University of Applied Sciences Mittweida; Mittweida, Germany
U. Loeschner, University of Applied Sciences Mittweida; Mittweida Germany
R. Ebert, University of Applied Sciences Mittweida; Mittweida Germany
P. Scully, University of Applied Sciences Mittweida, University of Manchester; - Great Britain
N. Goddard, University of Manchester; - Great Britain
B. Steiger, University of Applied Sciences Mittweida; Mittweida Germany
H. Exner, University of Applied Sciences Mittweida; Mittweida Germany
Presented at ICALEO 2011

The high repetition rate femto second laser technology joins together the advantages of ultra short laser pulses in micro machining and the industrial need of short processing times. However, the application of high repetition rate femto second lasers in material processing of metals shows novel laser matter interaction mechanisms, such as heat accumulation or particle shielding effects. The phenomena affect negatively the processing quality, so the basic understanding of the laser ablation process and the knowledge of suitable process parameters is essential. The paper presents a study of laser micro processing of metals by using a high repetition rate femto second laser. On stainless steel, copper, and aluminum the effect of the significant laser processing parameters, such as laser fluence, repetition rate, lateral pulse distance and polarisation, onto the machining process was investigated. The machining results were evaluated by the ablation rate, surface roughness, and the wall-angle. Outgoing from the results of the parameter study, optimized laser processing parameter are derived for laser micro structuring. Finally, the possibilities and the limits of the high repetition rate femto second laser technology in industrial application will be discussed by means of 3D micro processing examples.