Optimization of abrasive water jet machining parameters for basalt fiber/SiO ₂ nanofiller reinforced composites

Abstract To minimize machining‐induced delamination and surface roughness during abrasive water jet machining (AWJM) of basalt-fiber/silica dioxide (SiO 2 )-nanofiller epoxy laminates and to define process windows for high-quality holes/slots. Laminates were fabricated from basalt fiber mats (0°/90°) in an epoxy matrix containing 2–8 wt% SiO 2 nanoparticles. AWJM trials systematically varied cutting speed, abrasive flow rate, and stand-off distance (SOD), with jet pressure examined to interpret damage mechanisms. Responses included entry/exit delamination factor (image-based, equivalent-diameter metric) and surface roughness ( R a ), complemented by scanning electron microscopy (SEM) of cut edges. A response surface methodology (RSM) with multi-response desirability optimization was used to develop predictive models and identify optimal settings. Lower cutting speeds, moderate abrasive flow, and higher SOD consistently reduced delamination and improved surface finish; SEM revealed that higher jet pressure suppressed matrix washout and fiber pull-out, whereas low pressure increased surface defects. The RSM models showed strong predictive agreement with validation experiments, enabling contour maps and trade-off curves for concurrent delamination–roughness control. The study provides experimentally validated guidelines for precise parameter control in AWJM of basalt/SiO 2 laminates, supporting low-damage, assembly-grade machining of composite components. The resulting process windows are directly applicable to aerospace ( e.g ., brackets, panels, fittings), automotive (lightweight structures), and construction where surface integrity and structural reliability are critical.