On the temperatures developed in CFRP drilling using uncoated WC-Co tools Part II: Nanomechanical study of thermally aged CFRP composites

Abstract This study focused on the thermal degradation of the polymer phase of carbon fibre reinforced polymer (CFRP) composites through thickness by applying the nanoindentation technique. The results were compared for the elastic modulus (E) and hardness (H) of a non-aged sample and the samples aged at 200 °C and 350 °C during a short period of 60 s, in order to experimentally simulate the thermal conditions of drilling. Compared to the non-aged specimen, the results showed an increase of 16% in the elastic modulus and 12% in the hardness for the specimen aged at 200 °C. In contrast, the results for the specimen aged at 350 °C showed a variation of 0.8% and −3% in the elastic modulus and hardness respectively. These results contribute to a better understanding of the effect of the heat developed during the machining of composites on the properties of the resin phase in CFRP. Hereby we present the evidence of a post-curing effect at the temperatures close to the glass transition temperature (Tg) in the drilling of CFRPs.