Кинетика самозалечивания двойных композитов ZrB2-TaB2-SiC

Abstract

The work is devoted to the study of the self-healing kinetics of ceramic materials of the ZrB2-TaB2-SiC system, which has a dual composite structure, of the "composite in composite" type, where the matrix is represented by ZrB2-SiC, and the inclusions by TaB2-SiC. The studied ceramics were obtained by hot pressing with different ratios of the matrix and inclusions from 90/10 to 50/50. Sample with a homogeneous distribution of components served as a control. Surface defects were formed mechanically using blades and diamond pastes. The kinetics of self-healing was studied by heating in air at a temperature range from 1000 to 1500 °C. It is shown that all samples show a stable tendency to self-healing due to the decomposition of ionic-covalent compounds and the filling of defects with oxides with a large specific volume. X-ray phase analysis indicates the formation of borosilicate glass and zirconium oxide on the surface. A double composite with an 80/20 matrix-toinclusion ratio showed the highest self-healing rate at 1400°C.