Development of a Structural and Rheological Model for Investigation of Peculiarities of Deformation and Fracture of Metal-ceramic Composites with Multimodal Internal Structure

Paper is devoted to development of structural and rheological model for investigation of peculiarities of deformation and fracture of metal-ceramic composites in the framework of movable cellular automaton method (one of the representatives of discrete element methods in computational mechanics). Developed model takes into account main features of internal structure of metal- ceramic composites, such as wide size distribution of reinforcing ceramic inclusions, presence of wide transition zones between inclusions and metallic binder, etc. Using this model influence of width of interphase boundaries on the strength, the value of the ultimate strain and fracture energy of metal-ceramic composites was theoretically investigated. It is shown that the formation in the material of relatively wide interphase boundaries, characterized by a smooth change of the mechanical properties during the transition from the surface of ceramic inclusions into the volume of the binder, can significantly improve the mechanical properties (strength and fracture energy) of the metal-ceramic composite. This effect is connected with a significant decrease in stress gradient on the wide interphase boundaries.