Multiscale Interface Behaviour and Performance of GF-PC Composite

Abstract

Fibre-matrix interface performance is essential in fibre reinforced polymer composites, leading to important efforts in quantification and optimization. This is even more relevant for thermoplastics, since interfacial bonding happens only via physical interactions. Standardised mechanical tests provide homogenized composite properties, but fail to isolate the contribution of the interface. Micromechanical ones are designed for this exact purpose, but need complex set-ups and sample preparation. This study adopts a novel multiscale approach to measure mechanical properties of polycarbonate-glass fibre composites, manufactured under different interfacial conditions (sized & desized). This is enabled by use of focused ion beam in precise manufacturing and post-mortem analysis of specimens. The results show an evident difference between tested conditions at the macroscale (mode I), where sized specimens outperform desized ones. At the microscale (mode II), these differences are less pronounced due to the high ductility of the matrix resulting in a cohesive failure of the composite.