Microstructure and mechanical properties of pitch based mixture modified by additions of graphene oxide precursor and TiB2 particles

• Graphene Oxide (GO) modified coal tar pitch (CTP) increases its modulus and L a . • TiB 2 addition improves the ultimate strain and L c of carbon matrix in CTP. • Synergistic GO-TiB 2 addition has improved mechanical property and microstructure. • TiB 2 plays a key role in reducing C–C bonds oxidation and enhancing strength. Pitch based mixture as binder material is crucial component for structure stability and mechanical properties of carbon/graphite electrodes. In this work, coal tar pitch (CTP) mixture was modified by additions of graphene oxide (GO) precursor and fine TiB 2 particles. It is found that 1 wt.%GO addition increases the crystallite size, L a value and reduce the defects density of (0 0 2) planes in CTP mesophase and carbonization products with increased elastic modulus. The additions of 3 or 5 wt.%TiB 2 increase the stacking height of (0 0 2) planes ( L c ) of CTP pyrolysis and carbonization products with increased edge dislocation density and ultimate strain. The combined additions of TiB 2 and GO generate a synergistic effect on further improving the mechanical properties of CTP carbonization products with increasing the stacking order of (0 0 2) plane, crystallite size ( L a and L c ) and edge dislocation density. CTP-1GO-5TiB 2 shows a compressive strength 194.7 MPa higher than the pure CTP (155.4 MPa). Further findings suggest that a combined mechanism of GO and TiB 2 additions can be established through stabilizing C–C bonds while reducing C-O bonds along with chemical component transformations after pyrolysis and carbonization. TiB 2 particles play a key role in making the synergistic effect on improving the mechanical strength and reducing the oxidation of C–C bonds with additional increase in L a value.