This study investigated the tribological performance of hybrid composites composed of scrap carbon fiber (CF), glass fabric (GF), and polyamide 6.6 (PA6.6) through an innovative approach for reusing scrap CFs in high‐value composite structures. The experimental setup included CF/GF/PA6.6 hybrid composite laminates with varying CF contents and surface‐modified GFs, as well as PA6.6 sheets and GF/PA6.6 composite laminates. Solid particle erosion and scratch tests were conducted to assess the influence of scrap CF hybridization and GF surface modification on the tribological properties of the composites. The results demonstrated that neat PA6.6 sheets exhibited the lowest erosion rate, while the incorporation of CF and GF reinforcements had a detrimental effect on erosion resistance. The highest erosion rate was observed within the impact angle range of 15°–30° for pure PA6.6 sheets, whereas for composite laminates, it occurred within the range of 30°–45°. In contrast, CFs positively affected scratch hardness despite their negative impact on erosion resistance. Additionally, the silane treatment of GFs, which enhanced interfacial strength, improved the erosion resistance and scratch hardness of GF/PA6.6 composite laminates without CF. Profilometer‐based topographic analysis revealed a correlation between the average surface roughness of the eroded surfaces and the weight loss resulting from solid particle erosion.

Modern-day engineering applications favor polymers and polymer composites on the grounds of their high specific properties. They can offer many different advantages compared to metals; such as high strength-to-weight ratio, ease of production, but their erosion resistance is weaker. In polymer composites, material loss occurs because of high-speed and repeated exposure to erosive particles, therefore service performance and life of the parts are adversely affected. Due to this, it is crucial to predict the particle erosion that may occur in engineering applications and to know the erosive wear behavior of the materials well. Polytetrafluoroethylene and its composites are widely used in tribological applications because of their load-carrying capacity, self-lubricating, and low-density properties, but there is inadequate literature on particle erosion behavior. In this study, particle erosion behaviors of polytetrafluoroethylene, its randomly oriented short glass fiber, and carbon particle and bronze particle-reinforced composites were investigated under different test conditions. Two different types of erosive particles (garnet and alumina) were used to present the effect of erodent type on particle erosion behavior. After particle erosion tests, surface topographies were examined by an optical profilometer, and surface morphologies were examined by scanning electron microscopy. It has been found that the type of reinforcement and the type of erodent significantly affects the particle erosion behavior of polytetrafluoroethylene and its composites.

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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.