Process Parameters for Optimization in Abrasive Water Jet Machining (AWJM) of Silicon-Filled Epoxy Glass Fibre Polymer Composites

Silicon fillers have recently been employed as a multifunctional material to improve polymer composites' dielectric strength and mechanical strength, widely used to fabricate high-performance structural components. However, the mechanical strength was altered by adding silicon filler particles, leading to machining challenges that caused issues with quality and surface characteristics due to brittle fracture of silicon particles and related damage. The silicon filler 0, 3, 5, and 10% filled polymer matrix glass fibre reinforced composite was fabricated, and then abrasive water jet machining was used to investigate the machinability of the fabricated composite by considering silicon concentration, water jet pressure (^WP), standoff distance (^ND), traverse speed (^ST). The machinability of the composite was established for quality-affecting responses such as kerf taper angle (KT_A) and surface roughness (Ra). Silicon-filled polymer composites exhibit a higher dielectric constant than epoxy-glass fibre composites. An increase in silicon filler fraction decreases the surface roughness (Ra) and kerf taper angle (KT_A), specifically at 5% of silicon filler, resulting in better machining quality. In contrast, 10% silicon filler increases those two responses to a high level, resulting in lower usage in considered applications due to more direct interaction between silicon filler and garnet abrasive grains. Increasing water jet pressure (^WP) and decreasing standoff distance (^ND) and traverse speed (^ST) improve the machinability of silicon-filled composites. An SEM study of the surface topography reveals smooth cutting and finishing at high water jet pressure (^WP) and 5% silicon particles.