Interlaminar shear strength and tensile properties of environmentally-friendly fiber metal laminates reinforced by hybrid basalt and jute fibers

The mechanical properties of environmentally-friendly fiber metal laminates (EFFMLs) with jute (J)- basalt (B) fibers as a hybrid reinforcement and aluminum (Al) 2024-T6 as a skin, as well as an epoxy serving as a matrix, were investigated by employing tensile and interlaminar shear tests. Four hybrid structures including Al/J/J/B/B/J/J/Al and Al/B/B/J/J/B/B/Al as the sandwiched structures and Al/J/B/J/B/J/B/Al and Al/B/J/B/J/B/J/Al as the intercalated structures were fabricated. The results showed that the jute fibers sandwiched by the basalt fibers had the highest tensile strength, elastic modulus and interlaminar shear strength (ILSS) values; these were 213 MPa, 39.5 GPa, and 16.67 MPa, respectively. In contrast, these values were 139 MPa, 29.6 GPa and 10.3 MPa for the tensile strength, elastic modulus, and ILSS of the basalt fibers sandwiched by the jute fibers, respectively. Microstructural investigations also revealed that the jute fibers had some weak bonding with the aluminum layers, whereas the basalt fibers had the strong one with them. It was also found that the lack of diffusion caused the presence of empty spaces between the jute fibrils, and these defects were the main cause of the decrease in the mechanical properties.