An adaptive abrasive flow control system for maskless abrasive waterjet milling process

This study examines the implementation of the Adaptive Abrasive Flow Control System (AAFCS) in abrasive waterjet (AWJ) milling to mitigate over-erosion during the raster path machining cycle. The AAFCS adaptively reduces the abrasive flow during the deceleration of the cutting head in the raster path machining cycle, thereby causing less erosion on the workpiece material. Stainless steel is employed as the material to demonstrate the effectiveness of the AAFCS in mitigating over-erosion. Based on the preliminary experiments, the AWJ milling process parameters, such as a water pressure (P) of 250 MPa, a traverse rate (TR) of 1000 mm/min, an abrasive flow rate (AFR) of 0.32 kg/min, and a stand-off distance of 3 mm, are chosen for experimentation. Three AWJ-milled pockets, each measuring 50 mm by 2 mm, are carried out by increasing the step-over (SO) from 0.2 mm to 0.3 mm and finally to 0.35 mm. The developed AAFCS is ineffective in mitigating over-erosion at a 0.2 mm step-over due to a reduced traverse rate and increased AWJ overlap at the step-over regions, which extend the interaction time and expose the material to high-velocity AWJ plume, intensifying erosion. Contour analysis of AWJ milling reveals that AAFCS effectively mitigates the over-erosion effect at step-over conditions of 0.3 mm and 0.35 mm. The integration of AAFCS in maskless AWJ milling enhances its applicability in aerospace, electronics, and defense by minimizing material waste and optimizing machine resources and production time.