Mitigating drilling-induced damage and hot-wet aging effects through reconsolidation in CF/PEKK composites

This study investigates the impact of reconsolidation on the mechanical properties and damage recovery of carbon fiber reinforced poly ether ketone ketone (CF/PEKK) composites caused by manufacturing processes, particularly drilling, and environmental aging. Reconsolidation is performed using a hot-press method on both reference and aged composite samples. Mechanical properties are evaluated through compression and open-hole compression (OHC) tests, leveraging the digital image correlation (DIC) technique for deformation analysis. Additionally, thermal properties are characterized using dynamic scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). Before aging, compressive strength increases by 15.61% in compression samples and by 37.61% in OHC samples due to reconsolidation process. This recovery is further supported by enhancements in the glass transition temperature (Tg) and degree of crystallinity (Xc) by 5.97% and 20.94%, respectively. After aging, the compressive strength of the reconsolidated samples is slightly lower than that of the aged reference samples, yet still shows significant improvements in mitigating aging effects and reducing catastrophic failures. The DIC analysis further confirms that reconsolidation reduces delamination and catastrophic failures, confirming the reconsolidation process's efficacy in restoring mechanical integrity and performance.