Exploring the impact of abrasive water jet machining parameters on hole quality characteristics in Al2017A/hBN/ZrO2 hybrid composites

The quality of precision holes is essential in aluminium hybrid composites for aerospace and automotive applications, requiring tight dimensional tolerance. Abrasive water jet machining (AWJM) is appropriate for aluminium hybrid composites since it allows for precision cutting while minimizing tool wear, effectively managing the hard-soft reinforcement matrix combination. This research examines the impact of AWJM parameters on the quality of holes in Al2017A-based hybrid metal matrix composites that are reinforced with nano-hBN and nano-ZrO2. Three distinct compositions were synthesized through the stir casting method: Comp A, comprising 99.5 % Al2017A and 0.5 wt% n-hBN; Comp B, consisting of 98.5 % Al2017A, 0.5 wt% n-hBN, and 1.0 wt% n-ZrO2; and Comp C, which includes 97.5 % Al2017A, 0.5 wt% n-hBN, and 2.0 wt% n-ZrO2. Machining experiments were conducted utilising a Taguchi L27 orthogonal array, with water pressure, traverse speed, abrasive flow rate, and stand-off distance as factors. The evaluation of hole quality metrics, including cylindricity, circularity, roundness, and hole damage factor (HDF), was conducted using mean effect plots and response surface methodology. Comp B showed the lowest circularity error of 0.2661 mm, the highest roundness of 0.991, minimal cylindricity, and the lowest HDF among all variants. It was determined that medium water pressure (225 MPa), medium traverse speed (120 mm/min), high abrasive flow rate (450 g/min), and large standoff distance (4 mm) minimized cylindricity error and hole damage factor, while simultaneously improving circularity and roundness. These factors significantly enhance hole dimensional accuracy, defining a process-geometry framework for the precision machining of high-performance hybrid components.