The effect of cooling rates on crystallization and low-velocity impact behaviour of carbon fibre reinforced poly(aryl ether ketone) composites

Crystallization of poly(aryl ether ketone) (PAEK) plays an important role in the impact resistance of composite laminates but it is still unclear how the cooling rate affects the performance. In this paper, carbon fibre (CF) reinforced new copolymer PAEK and commonly used poly(ether ether ketone) (PEEK) were fabricated by furnace cooling and water cooling. The effects of cooling rates on the crystallization behaviour of thermoplastics, interfacial bonding strength, interlaminar fracture toughness and low-velocity impact performance of composites were studied. Results show that the crystallization and the crystalline size of PAEK are smaller than those of PEEK at the same cooling rate. In composites, the lower crystallinity and smaller crystals of the matrix are conducive to improving the matrix ductility and interfacial bonding strength. Under the water-cooling condition, the impact damage area CF/PAEK is about 71% lower than that of CF/PEEK, while the CAI is about 14% higher.