Recent developments in ultrasonic welding of similar and dissimilar joints of carbon fiber reinforcement thermoplastics with and without interlayer: A state-of-the-art review

Abstract

Ultrasonic welding (USW) is utilized to join identical and non-identical materials, with and without a thermoplastic composites or thermoset composites coupling layer, or with different shapes of energy directors or adhesive materials. Due to its emerging structure, joining carbon fiber (CF)-reinforced polymer has become imperative due to the developed concerns in different industrial and manufacturing sectors. This review article covers all types of joined CF-reinforced polymers, including similar/dissimilar CF-reinforced thermoplastics or CF-reinforced thermosets joined by USW, considering different types of USW (spot welding, continuous welding). This review considers various welding process parameters and their impacts on welding quality, welding strength, and mechanical and microstructure characterizations of the welded joint. Also, improving the USW joints and their challenges are discussed. The fabrication processes of the polymer matrix composite and various polymers are addressed. In addition, the recyclability of CF-reinforced polymer is highlighted. A key finding from this review is that polyetheretherketone and both types of nylon (PA6 and PA66) show high exceptional characterizations, making them more favorable for developing CF-reinforced thermoplastics over other types of polymers. While a unique co-curing process must be completed for the adhesive material before performing the USW, welding energy is the most effective process parameter that enhances the mechanical properties when using adhesive bonding before USW.