YB2C2: The first damage tolerant ceramic with melting point over 2500 C-?

The ultra-high temperature thermal stability of YB2C2 between 2300 oC and 2550 oC in argon was systematically investigated by induction heating method. The phase composition and microstructure of the samples after heat treatment at different temperatures were characterized with X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The results show that YB2C2 has excellent ultra-high temperature thermal stability, and it can maintain the structure and phase stability after heat treatment at 2500 oC for 20 min. It would melt rather than decompose with the rising of the temperature. The melting point of YB2C2 is between 2500 oC and 2550 oC, and it has great potential for future ultra-high temperature applications.