Impact of the aging process in composite materials under solid particle impact wear

In the present work, the effect of saline water on the tribological properties of laminated composite materials reinforced with marine glass and Kevlar fibers is studied for possible applications in hydrokinetic turbine blades. For the manufacture of the composites, the vacuum-assisted resin infusion process was used. Epoxy, vinylester, and hybrid polymer resins (epoxy with vinylester), reinforced with unidirectional glass fibers, applying on their surfaces layers of 0/90° bidirectional marine glass fiber and plain weave Kevlar fabric were used. The proportion used was 50% fiber and 50% resin. The specimens obtained (40 mm × 30 mm × 4 mm thick) were exposed to an accelerated aging process in saline water at 70°C for 1176 h, all up to the point of moisture saturation, which simulates seawater conditions. For the wear tests, sea sand particles were impacted at a pressure of 4.5 bar, impact angle of 90° and impact speed of 5.8 m/s. A diameter of 10 mm of the nozzle, a distance of 5 mm between nozzle and specimen and a total time exposure of 12 minutes were used. In aged composites, the one with the greatest depth of wear is presented in the VMGF material with 210.51 µm, compared to the EKF material with 31.51 µm, which represents a difference of 85.03%; while, in the unaged composites, the material with the greatest depth of wear is presented in the VMGF, with 606.55 µm, with respect to the EKF, with 84.52 µm, which represents a difference of 86.06%. The results demonstrate that saltwater-aged materials absorb greater impact energy with respect to unaged material, obtaining greater resistance to erosive wear.