Microscale simulation method for prediction of mechanical properties and composition design of multilayer graphene-reinforced ceramic bearings

Abstract Herein, a microscale simulation method for the prediction of mechanical properties and composition design of multilayer graphene (MLG)-reinforced ceramic bearings was presented. The method aims at improving the toughness of the ceramic bearings and overcoming the disadvantages of the trial-and-error approach implemented in the research of ceramic bearings. Considering the most widely used Si3N4 ceramic bearing as an example, the microscale models of 1–4 wt% MLG-reinforced Si3N4 ceramic bearings were established using the Abaqus software and on the basis of the ASTM standards. The simulation results obtained through the proposed method and the previously reported experimental results for the mechanical properties demonstrated good agreement. The simulated optimal MLG content value of 1 wt% was consistent with that reported in previous studies, which confirmed the effectiveness of the proposed method. The flexural strength and fracture toughness of the MLG-reinforced Si3N4 ceramic bearings reached the maximum values of 761.77 MPa and 7.23 MPa m1/2 upon the addition of 1 wt% MLG, which were enhanced by 25.85% and 59.96%, respectively, compared with monolithic Si3N4 ceramic bearing. Conversely, the introduction of MLG imparted a softening effect on the Si3N4 ceramic bearings and, therefore, showed reduction in bearing hardness. Moreover, the MLG bridging phenomenon, previously observed experimentally, was revealed through simulation for the first time, which provided an explanation for the toughening mechanism.