Understanding and Modeling the Effect of Fiber Type on the Crystallization Kinetics of a Thermoplastic Matrix Composite (Masterarbeit)

Abstract

Semi-crystalline thermoplastics are increasingly used as matrix materials in fiber-reinforced composites within the aerospace industry. Their ability to crystallize is a critical property that significantly influences the final product and must therefore be considered in process simulations. A promising new material in this area is CF/LM-PAEK. However, the few existing material models are typically tailored to specific fiber-matrix combinations from a single manufacturer. In this study, the influence of different fibers on the crystallization kinetics of CF/LM-PAEK was investigated using non-isothermal differential scanning calorimetry (DSC). Experiments conducted at cooling rates ranging from 5 to 90°C revealed that the fiber type significantly affects the crystallization kinetics, while the fiber volume fraction does not. Notably, at higher cooling rates, significant differences in crystallization temperatures and rates were observed. These findings provide a valuable foundation for future morphological studies. Additionally, the study examined whether an existing material model could adequately predict the crystallization kinetics for a different fiber type. However, fitting the induction sub-model to data from a different material revealed that accurate predictions require further model adjustments.