A NEW CLASS OF 'IN-SITU' FIBER REINFORCED BORIDE COMPOSITE CERAMIC MATERIALS

摘要

There are developed the physical grounds of creation of the new type of advanced ceramic -ceramic composite materials based on eutectic mixtures of rare earth and transition metals boride phases. It is worked out the process of directional crystallization of such compositions, that results in "in-situ" formation of their specific real structure, consisted from single crystal matrix of rare earth boride, strengthened, also, by, regularly distributed into it, single crystal whiskers of transition metal boride. Received composites possess useful inherent matrix component properties simultaneously with high mechanical properties, that distinguish them from common ceramic materials. The main attention is paid to LaB_6-ZrB_2 system that could be of interest as thermal-shock resistant effective cathode material for electron-beam sources.