THE MECHANICAL-BEHAVIOR OF PEEK SHORT-FIBER COMPOSITES

Short glass (GF) a nd carbon fibre (CF) reinforced poly-ether-ether-ke tone (PEEK) composites were prepared by injection moulding and then mi crostructurally characterized. Their mechanical behaviour was determin ed by two different methods: a classical unidirectional tensile test a nd an immersion ultrasonic technique. The reinforcing effect of fibres is discussed in the context of the theory of reinforcement of Bowyer and Bader. Interfacial shear strength and critical fibre length at bre ak are calculated for both PEEK/GF and PEEK/CF composites. Examination s of fracture surfaces of uniaxial tensile specimens revealed a higher adhesion of carbon fibres to PEEK matrix in regards to the adhesion c oncerning glass fibre-PEEK interfaces, which is in agreement with the results provided by the model. Compatibility of ultrasonic and tensile results is reported.