Kotenko V. Physical Regularities of the Mechanical Behavior of Composites with a Ceramic Matrix under Local Loading

The present work is devoted to the analysis of fracture conditions of brittle bodies under the action of local and impact loads, which is their most often encountered application. In the work, a new model of indentation of brittle materials was tested on a wide range of composites with a ceramic matrix (CCM), the structure of the region of their contact fracture was experimentally investigated, and regions characterized by different geometries of cracks and different mechanisms of fracture were distinguished. In the frame of the new indentation model, a relation between the value of the contact pressure (hardness HM) and strength characteristics for composites with a ceramic matrix was determined, and original procedures for the certification of their mechanical properties under local loading (contact tensile strength and contact compressive strength) were proposed. The interrelation between the parameters of structural inhomogeneity of ceramics and statistical characteristics of contact strength (theWeibull modulus) is shown. By the example of new composites with a ceramic matrix, namely B4C-МеB2 (Mе-Ti, Zr, V, Cr), B4C-SiC, and TiN-AlN, relations between the structural characteristics (volume contents ofphases, structure dispersity, porosity, and the level of internal stresses), the contact strength, and their operating characteristics were established. The results are important for solid-state physics and physical materials sciences, in part of development physical principles of constructing CСM with high wear- and impact resistance.