Adhesive and impact strength of hybrid layered metal-polymer composites reinforced by basalt fiber

This work shows the possibility of obtaining hybrid layered metal-polymer composites based on low-carbon steel and aluminum alloys with interlayers of basalt fiber reinforced thermoplastic polymer — polyetheretherketone by methods of hot and cold bonding with the use of hot and cold curing adhesives, respectively. The adhesive tear and shear strength of composites obtained by two alternative methods and the impact strength of steel-polymer and aluminum alloy-polymer joints were evaluated. The tests of five-layered composites for impact bending on samples with “crack-arrester” type V-notch (with the orientation of the notch line across the composite layers) at temperatures of −60, +20, and +200°С were carried out. The analysis of the test results showed that the composites have increased strength at shear loads and resistance to brittle fracture at low climatic and high working temperatures. Fractographic analysis of the fracture surface of composites allowed to determine that the fracture proceeds through adhesive, cohesive, and mixed mechanisms. Cohesive fracture is initiated in the polymer layer by nucleation and crack growth along the fiber-matrix interface, as well as cracking of the basalt fibers.