Interlaminar bonding of high-performance thermoplastic composites during automated fiber placement in-situ consolidation

Interlaminar property is an important indicator to evaluate the overall quality of composite components. In the process of automated fiber placement (AFP) in situ consolidation, the interlaminar properties of the composite are affected by the processes such as temperature history, polymer degradation and crystallization, interlaminar bonding, and void dynamics. Interlaminar bonding is the primary process of forming the overall structure between layers of the component. In this study, the interlaminar bonding process of CF/PPS composites and the interlaminar properties of the laminates fabricated by AFP in situ consolidation were investigated. The influence of the processing parameters on intimate contact, polymer healing, and interlaminar bonding was analyzed through theoretical models. Taking the interlaminar shear strength of the laminates as an index, the model results were verified by experiments. The time required for diffusion of polymer molecular chain was much shorter than that of intimate contact. For the CF/PPS system used, the intimate contact process was found to be the control factor of interlaminar bonding. Furthermore, the results of the degree of intimate contact indicated that the ideal rectangular surface model was more consistent with the experimental values.