Enhanced thermo-mechanical performance of TiB₂-reinforced CF/PEEK composites processed by high-temperature compression moulding

Carbon fiber reinforced poly-ether-ether-ketone (CF/PEEK) composites were fabricated using a high-temperature compression moulding process, and the influence of titanium diboride (TiB₂) nanoparticles (0–4 wt%) on their thermo-mechanical performance was evaluated. The process enabled effective filler dispersion and consolidation at elevated moulding temperatures (350–370 °C). Compressive strength tests performed on CF/PEEK specimens with 2 wt% TiB2 reinforcement revealed maximum values of 201.5 MPa at 370 °C. The addition of TiB₂ primarily enhanced hardness and thermal behaviour. Rockwell hardness improved slightly with temperature and the values at different combinations (0-4wt%) TiB₂ reinforcement were discussed. SEM analysis confirmed uniform TiB₂ distribution and stronger fibre–matrix–filler bonding, while microstructural voids remained a limiting factor. Thermal studies showed excellent stability, with TGA indicating degradation onset above 550 °C and 65% char residue at 800 °C. DSC confirmed the semi-crystalline nature as both Tg (288 °C) and Tm (345 °C) were recorded, thus confirming the fact that stable crystallization of the hybrid composite has occurred. Overall, the findings prove that compression moulding at high temperature enhances CF/PEEK densification and bonding, besides promoting improvement in hardness and thermal resistance due to the presence of TiB₂. In case there is some further process optimization to reduce porosity, then TiB₂-reinforced CF/PEEK composites show strong prospects as lightweight, high-performance material for aerospace, automotive, and high-temperature structural applications.