A numerical model to prevent the thermal degradation of CFRPs at extreme heating rates – The laser processing of CF/PEEK

This study proposes a coupled thermal-chemical numerical model for preventing the thermal degradation of carbon fibre (CF) reinforced polymers at extreme heating rates. Its applicability is demonstrated in a laser-heating case study of CF-reinforced poly-ether-ether-ketone (CF/PEEK). The kinetic parameters of the PEEK matrix, derived from thermogravimetric analysis at conventional heating rates, are introduced in the model and an extrapolation approach is applied to investigate the laser heating of CF/PEEK. The results show that the model captures the heating rate effect on the decomposition of the material, and is used to identify the processing conditions that can reach high temperatures without triggering the thermal degradation mechanisms of the PEEK matrix. Then, a multi-technique experimental investigation takes place to identify the processing conditions that first trigger the thermal degradation mechanisms of CF/PEEK in the examined laser-heating case study. Interestingly, a good agreement is found between the experimental and numerical investigations which validates the model and the applied extrapolation approach.