Elevated-Temperature Thermal and Mechanical Behavior of Carbon Fiber/Graphite/PTFE/PEEK Composite

摘要

Elevated-temperature thermal and mechanical properties of carbon fiber(CF)/graphite flakes (Gr)/PTFE filled PEEK composite are investigated by acombined experimental and theoretical study. In the experimental phase, theCF/Gr/PTFE/PEEK composite was fabricated by compression-molding, followed by asintering process. Optical and electronic microscopy was performed to examinemicrostructure of the composite and X-ray diffraction (XRD) was conducted toprovide morphological information. Dynamic-mechanical analysis (DMA) wasperformed to evaluate composite thermomechanical properties. Differential scanningcalorimetry (DSC) and thermal-mechanical analyzer (TMA) were employed todetermine heat capacity, glass transition temperature (Tg), coefficient of thermalexpansion (CTE) and thermomechanical preperties of the composite at elevatedtemperature. To augment the experimental study, micromechanics modeling andanalysis of the composite thermal and mechanical behavior are also conducted tobetter understand the fundamental nature of composite microstructure andenvironmental interaction. Good agreement was observed between the experimentaldata and theoretical predictions. The detailed effects of elevated temperature onCF/Gr/PTFE/PEEK composite thermoelastic (storage) and viscoelastic (loss) moduli,thermal expansion and heat capacity are determined.