Способы повышения механических характеристик керамики на основе диборидов циркония и гафния (Обзор)

Abstract

This paper describes the main methods for improving the mechanical properties of ceramic materials based on zirconium and hafnium diborides, such as strength and crack resistance. Particular attention is paid to the influence of the sintering method, as well as additives introduced into the powder composition, in particular hard fibers, second-phase powder particles and “whiskers”, on the mechanical characteristics of the ceramics. On the basis of the analysis of literature data, it is shown that the spark plasma sintering (SPS) method allows to obtain ceramic samples with increased mechanical characteristics due to their high density and low defects. The addition of silicon carbide filamentous crystals or fibers to the ceramics can increase the crack resistance of the sintered material up to 6.0–8.5 MPa×m1/2. These conclusions can be useful in the development of ultra-high-temperature ceramic materials.