Abstract
Composites are increasingly employed in aerospace, automotive, construction, sports, and defense industries owing to their high strength-to-weight ratio, corrosion resistance, and customizable properties. This study focuses on sisal fiber reinforced epoxy composites with sawdust fillers from three Ethiopian hardwood species: Aningeria (Kerero), Cordia Africana (Wanza), and Cedar (Tid). Using Taguchi design of experiments (L9 orthogonal array), nine composite samples were fabricated by the hand lay-up method with fiber orientations of 0/90°, 0/45°, and random. Mechanical (flexural, compression, impact), tribological (wear), physical (water absorption), and morphological (SEM) properties were systematically evaluated. Results revealed that Aningeria sawdust composites with 0/90° fiber orientation and 10 wt% filler exhibited the highest flexural strength (90.08 MPa), superior impact strength (78.4 kJ/m(2)), and lowest water absorption (0.53% after 72 h). Cordia Africana sawdust composites with 0/90° orientation and 20 wt% filler demonstrated the highest compressive strength (87.97 MPa) and optimal wear resistance (18 μm). Statistical analysis identified fiber orientation as the most significant factor (p < 0.05), contributing 73.27% to flexural strength and 90.12% to wear resistance. The study demonstrates that sisal fiber composites reinforced with locally available sawdust fillers provide an eco-friendly alternative to conventional synthetic composites, with promising applications in structural and defense components where balanced mechanical performance and sustainability are required.