ABSTRACT
The desire for environment-friendly materials and sustainability has brought a paradigm shift in the way engineers and the entire material research community thinks while attempting to develop new material, particularly for engineering applications. This study is carried out to underscore the suitability of particulate moringa oleifera fruit pod (MOFP) reinforced epoxy bio-composites on selected properties for structural applications. The dried waste fruit pods were processed as calcined and pulverized fruit pod particulates, respectively. Their respective bio-composites were developed by blending the selected materials in predetermined proportions using the open mould processing method. The MOFP particles were characterized with SEM/EDS and XRD while mechanical and wear properties of the developed bio-composites were evaluated. The results showed that the pulverized MOFP reinforced epoxy bio-composites showed improved properties than the calcined MOFP bio-composites in most of the properties considered. This was noticed to be due to the presence of more elemental constituents and at higher proportions in pulverized particles than in the calcined particles. It was discovered that 15 wt.% pulverized MOFP reinforced epoxy bio-composites gave about 67.9%, 28.7%, 8.8%, and 8.8% enhancement and with a value of 70.2 HS, 39.02 MPa, 198.4 MPa, and 753.28 MPa in hardness, flexural strength, flexural modulus, and tensile modulus, respectively to emerge as the reinforcement content with the optima properties. Based on the findings, MOFP particles reinforced epoxy-based biocomposites can be used in applications where stiffness and high strength are not essential requirements; packaging applications; in electrical component applications such as circuit boards, and cables due to their low thermal conductivity.
ABSTRACT
Nanoindentation is a viable method to assess the mechanical properties of developed alloys and composites at the nanometer scale without hampering the microstructure and integrity of materials. In this study, nondestructive measurement was conducted on spark plasma sintered nickel aluminium bronze (NAB), and graphene nanoplatelets (1, 2, 3 wt.%) reinforced NAB composites using the nanoindentation technique. The nondestructive measurements were conducted under loads of 50 mN and 100 mN to assess the nanohardness and reduced elastic modulus of the fabricated NAB alloy and composites. Further investigations were carried to evaluate the elastic recovery index, plasticity index, the nanohardness and reduced modulus ratio, and the yield pressure to reveal the nanomechanical responses of the fabricated materials. Scanning electron microscopy was used to analyze and reveal the dispersibility of the graphene nanoplatelets (GNP) in the NAB matrix. The nondestructive measurements showed that the nanohardness, reduced elastic modulus, yield pressure, resistance to elastic strain to failure and the elastic recovery index improved with the presence and increase in the concentration of GNP in the NAB matrix. The reduced elastic modulus and nanohardness values range from 34.2 - 43.0 GPa and 4407.2-6598.8 MPa respectively, which declined with nanoindentation loads. The fabricated NAB alloy experienced the maximum plastic deformation and least resistance to impact loading.
