Influence of process parameters on kerf geometry in fine laser cutting of 6061 Al alloy

In the present work, laser cutting of 6061-T6 aluminium alloy sheets, 1 mm in thickness, was investigated using a 150W lamp pumped Nd:YAG laser, characterised by pulse power up to 3 kW. The study was divided in two steps: first, in order to find the maximum cutting speed, defined as the speed beyond which it is not possible to cut the sheet, cutting pre-tests were performed at a fixed average power (150W), changing the pulse duration (i.e. the pulse power and the pulse energy) and the cutting speed; then, in order to assess the influence of the process parameters on kerf geometry and roughness, a second set of tests was carried out, and a full factorial design 3^2x2 was adopted according to the DoE methodology. In order to determine which of the process parameters affects the kerf geometry and how, Analysis Of VAriance (ANOVA) was used. Experimental results show the possibility to obtain kerf characterized by narrow width, low perpendicularity, low dross height and low roughness, resulting in a fine cut on a 6061 Al alloy.