State-of-the-art review on developing lightweight fiber-metal laminates based on synthetic/natural fibers

Abstract

The development of hybrid materials consisting of alternating layers of metal alloys and polymeric composites has revolutionized the engineering field. These metal-composite laminates combine the merits of each individual component, forming advanced and promising structures which could be employed for structural applications. The low fatigue crack growth rate and high damage tolerance of these materials are particularly fascinating. When developing metal-composite laminates with superb functional properties, the combination of several metal surface treatment techniques is a common practice to ensure optimum metal-composite adhesion. Today, a new cutting-edge manufacturing technique utilizing nano-porous network film has been established to get rid of the massive infrastructure of conventional autoclave techniques and produce first-rate materials. Even though various techniques can be adopted to manufacture metal-composite laminates, the selection of the techniques is highly dependent on the nature of the polymer matrix. After the manufacture of the metal-composite laminates, post-stretching is considered a critical step to alleviate the unfavorable residual stress to ensure the optimum performance of these materials for long-term service. When dealing with natural fibers, it is worth mentioning that the processing temperature should be limited to below 200°C regardless of manufacturing technique to avoid fiber degradation. Metal-composite laminates consisting of synthetic/natural fibers are considered a viable option to offset the demerits of each kind of fibers. By incorporating fatigue-resilient natural fibers in the laminates, it is expected that the overall fatigue resistance of the laminates can be apparently enhanced, which is in line with the initial goal of developing metal-composite laminates. Highlights: Fiber bridging offers fiber-metal laminates with superior fatigue properties. Metal surface treatment is vital to ensure an optimum fiber-bridging mechanism. A novel out-of-autoclave method can produce first-grade fiber-metal laminates. Post-stretching is needed to lessen residual stress in fiber-metal laminates. Hybrid fiber-metal laminates are feasible for structural applications.