Interphase evaluation and nano-mechanical responses of UHMWPE/SCF/nano-SiO2 hybrid composites

The nano-mechanical properties of UHMWPE-based hybrid composites were explored using nanoindentation and nanoscratching methods. Composite samples were fabricated by melt mixing using short carbon fibers (SCFs) and nano-SiO2 particles as reinforcements. A standard Berkovich indenter was used for indentation and scratching under normal loads of 100 and 300 μN, respectively. The indentation hardness and elastic modulus of the carbon fiber, polymer matrix and interphase of the composites were investigated. The frictional responses of these 3 regions and the estimated length of the interphase were evaluated by nanoscratching. The results showed noticeable differences between the frictional response, hardness and elastic modulus of these regions. Furthermore, the nano-mechanical properties of the composite increased considerably in the presence of the nano-SiO2 reinforcement.