Study of abrasive water jet machining (AWJM) of coir/banana epoxy composites by adding of fly ash fillers

The study set out to determine how varying proportions of fly ash filler affect the workability of hybrid Banana (B)/Coir (C)fiber reinforcing composites. Useful applications were found for fly ash produced from biodegradable materials as Bagasse Fly ash (BGFA), Banana Fly ash (BFA), and Coir Fly ash (CFA). Surface roughness and Material Removal Rate (MRR) are negatively affected by the high hardness of 6% Bagasse Fly ash (23.16 HV) and 6% Coir Fly ash (24.39 HV) in composites. The highest MRR, at 378.72 mm3 min−1, was achieved with a 6% BGFA mixture, a water jet at 260 MPa, a standoff distance of 1 mm, a traversal speed of 20 mm mm−1. MRR was determined to be 355.54 mm3 min−1 for mixtures containing 2% CFA and 2% BFA, and 354.84 mm3 min−1 for mixtures containing 2% each. BGFA, CFA, and BFA composites with 6% BGFA, 2 % CFA, and 2% BFA had the smoothest surfaces, with values of 6.44, 6.76, and 6.8 µm. The filler surface's good adherence to the matrix mitigates the erosion of fibre particles at higher WP. Low fiber/matrix bonding in untreated fibres led to poorer machining properties. Cracks and matrix breakages were found to be reduced by using filler powders.