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The Metal Sheets Processed by AWJ. Analysis of the Surface Quality

Abrasive water jet (AWJ) is a nonconventional machining process in which abrasive grains in a high-speed water jet collide with the sample and erode it. This technology has been developed as an alternative to the conventional processes in order to facilitate the processing of hard materials as stainless steel, titanium alloys, composite materials, etc. However, it is not limited only to hard materials, since it has been successfully applied to process softer materials as aluminum, copper, plastics. Also, the abrasive water jet technology can be used both, to process thin metal sheets and plates since it offers many advantages such as: good surface quality, no thermal distortions, minimal burrs, low machining force, high flexibility. The aim of the current paper was to study the surfaces quality of samples made by aluminium, A1050, processed by AWJ in case of using different working regimes. The experimental tests have been performed on the Hydro-jet Eco 0615 water jet cutting machine. The parameters that have been varied were pressure, feed rate, abrasive quantity, distance between the cutting head and working sample while the diameter of focusing tube and diameter of water nozzle have been kept constant. The parameters taken into account to quantify the quality of the processed surface were those defined in the ISO/WD/TC 44 N 1770 standard (fig. 1): width of the processed surface at the jet inlet (Li), width of the processed surface at the jet outlet (Lo), deviation from perpendicularity (u), inclination angle (α) and roughness (Ra).