Self-healing in high temperature ZrB2-SiC ceramics

Abstract

High-temperature composite materials based on ZrB2-SiC are promising for creating heat-protective multi-cycle structures operating at temperatures over 2000° due to high heat resistance and low specific gravity. In the research the defects self-healing kinetics of high-temperature ZrB2-SiC ceramic composites in the temperature range of 1200-1600° was studied. It has been shown that one of the most effective defects self-healing process was observed after annealing at a temperature of 1600°, regardless of the SiC content. At the same time samples annealed at 1200 and 1400° were significantly inferior in healing ability, despite the increasing of the isothermal exposure time. For all studied composites increasing of the heat treatment duration provided increase of the self-healing percentage. Moreover, defects were eliminated more quickly in ceramics with silicon carbide content of 15 and 20 vol %.