Development of artificial human prosthetic using Hordeumvulgare husk silicon oxynitride and Pterospermumacerifolium stem fibre reinforced epoxy composite

Abstract

This work investigates the mechanical, impact, shear, and morphological properties of epoxy-based composites reinforced with 40 vol.% Pterospermumacerifolium stem fiber and Hordeumvulgare husk-derived silicon oxynitride. The addition of fibers increased the tensile strength from 53 MPa (neat epoxy) to 109 MPa and flexural strength from 68 MPa to 128 MPa, while the incorporation of silicon oxynitride as a nano-filler further enhanced the properties. Among the composites, EPS2 (3 vol.% silicon oxynitride) exhibited the highest mechanical performance, with tensile strength of 145 ± 4.4 MPa, flexural strength of 161 ± 5.1 MPa, and Izod impact strength of 4.6 ± 0.14 J, demonstrating optimal fiber-matrix interaction and reinforcement efficiency. In high-velocity impact testing, EPS2 absorbed 6.8 ± 0.24 J with an extended impact duration of 14.3 ± 0.6 ms, while total energy absorption reached 38.7 ± 1.3 J with a deflection of 3.8 ± 0.14 mm. EPS2 also displayed the highest V-Notch shear strength (21.4 ± 0.8 MPa) and rail shear strength (22.4 ± 0.9 MPa), confirming enhanced shear load-bearing capacity. SEM analysis revealed uniform filler dispersion and strong fiber-matrix adhesion, minimizing voids and enhancing mechanical stability, whereas excessive filler content in EPS3 led to agglomeration and reduced performance. Overall, EPS2 demonstrated the best balance of strength, toughness, and impact resistance, showing minimal perforation, negligible delamination, and superior energy dissipation, making it the most suitable composition for structural applications requiring high mechanical integrity.