Polymer Composites, cilt.44, sa.9, ss.6212-6227, 2023 (SCI-Expanded)
In this study, various heat treatments (annealings) were applied to carbon fiber reinforced polyetheretherketone (CF/PEEK) samples at four different temperatures (185, 225, 265, and 305°C) along two different holding times (30 and 270 min). The effects of changing matrix morphology, degree of crystallinity, and fiber-matrix interface properties on thermo-mechanical properties were investigated by differential scanning calorimetry (DSC) and dynamic mechanical analysis analyzes. Also, annealed CF/PEEK samples were tested to determine solid particle erosion characteristics. It was observed that the matrix crystallinity, fiber/matrix interface properties, and tribological properties of the CF/PEEK composites changed significantly with the thermal history. There was an increase in the degree of crystallinity with the increase in annealing temperature. It was observed that the degree of crystallinity increased up to about 27% and the damping factor decreased up to about 45%. As a result of the solid particle erosion tests performed under normal impact conditions, it was determined that the formation of the transcrystalline layer formed by heat treatment adversely affected the solid particle erosion resistance of the CF/PEEK. Erosion resistance of the heat-treated samples (having higher fiber/matrix interface) was approximately 50% lower compared to the quenched sample. While the erosion rate for quenched samples is 14.5 × 10−5 g/g, this rate rises to 26.1 × 10−5 g/g for annealed samples. In addition, surface topography was examined by means of an optical profilometry, and surface morphology was examined by means of scanning electron microscopy. These examinations confirmed the experimental results.