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The aim of the paper is to optimise the microholes machining, in the case of laser drilling. The laser used for experimentswas a Neodim-15 laser. The material used for drilling was 4lMoCrl 1 austenitic stainless steel with a 1,5 mm thickness. Asparameters of the laser drilling process were considered: diaphragm diameter, focal point position, focal length of the lensand laser pulse power. The objective functions were the diameter of the microhole in the area of the laser beam entrance in material (Di), the diameter of the microhole in the area where the laser beam exit the material (De), respective their tolerances (Ti and Te). It was used an complete factorial experiment 2. The established mathematical models are useful infinding the optimum values of the parameters in various combinations, such as the hole diameter to be closer to the requireddiameter.Keywords: laser drilling, experimental design, laser process optimisation 1. EXPERIMENTAL CONDITIONS The aim of the paper is to optimise the process which realise microholes broke through stainless steel 4lMoCrl 1and obtention of some orifices whom effective sizes will got smaller deviations from nominal quatation.For these experiments we used Neodim 15 laser instalation which functioned in pulses. This instalation havepossibility to regulate the pulse power in range of2,5-12 J.The material used for drilling was austenite stainless steel, in sheets with a 1,5 mm thickness. Every experimentwas repeated five times, for a better investigation.The extreme values were eliminated and the arithmetic average of the remaining three values was used for the nextstage of results processing.The impulse power (X1),the diaphragm diameter (X2), the focal point position (X3),and the focal lenght of focusobjective (X),were considered like parameters oflaser drilling process. |
