Advances and evolution of thermoplastic composite materials for aerospace structures: A comprehensive review

Thermoplastic composites have been adopted in aerospace mainly as substitutes for thermosets, facilitating recyclability and reuse, extended shelf life, and expedited manufacturing, which have gained significance due to stringent production rates and sustainability objectives. Progress in aerospace-grade PPS and PAEK systems, along with advancements in automated forming and welding, has facilitated the transition from localized substitutes to extensive structural integration. Contemporary aircraft utilize thermoplastic composites not merely as isolated replacements; they now encompass aviation systems hardware, high-volume secondary aerostructures, and progressively integrated airframe substructures facilitated by the fusion welding of PEEK/PEKK-based architectures. The future direction is towards highly automated, weld-focused assembly, enhanced by in-process monitoring, nondestructive inspection, and certification-ready durability proof. At the same time, circularity initiatives concentrate on scalable end-of-life recovery methods for fiber-reinforced thermoplastics.