Gamma radiation treatment of carbon fabric to improve the fiber–matrix adhesion and tribo-performance of composites

Fiber–matrix interfacial bonding plays a critical role in controlling performance properties of the composites. Carbon fibers have major constraint of chemical inertness with the matrix and need surface treatment to improve the adhesion with the matrix. In this work, gamma irradiation technique with varying doses (100–300 kGy) was employed to carbon fabric (CF) to develop composites with polyetherimide (PEI) matrix based on impregnation method followed by compression molding. Composites were characterized for interlaminar shear strength (ILSS) and adhesive wear studies against mild steel disc under various loads. Improvement in the friction and wear properties was correlated with the improvement in ILSS as a result of CF treatment. Higher the dosing, higher was the enhancement in ILSS and tribo-performance of composites. Fourier transform infrared spectroscopy (FTIR) indicated inclusion of functional groups (mainly carbonyl). SEM studies on fibers indicated roughening of the surface as a consequence of treatment. Both these factors were thought to be responsible for enhancing the fiber–matrix interface. For in depth analysis, various techniques such as fiber tension test, adhesion test and Raman spectroscopy analysis of CF were also exploited.