Porous YbB 6 Ceramics Prepared by In Situ Reaction between Yb 2 O 3 and B 4 C Combined with Partial Sintering

Porous YbB 6 ceramic, a member of the ultrahigh‐temperature ( UHT ) family, is successfully prepared from Yb 2 O 3 and B 4 C powders by in situ synthesis combined with partial sintering method. Due to the fact that pores can be produced using the gases such as B 2 O 3 and CO generated in reaction between Yb 2 O 3 and B 4 C, phase‐pure porous YbB 6 ceramics are obtained after sintering the Yb 2 O 3 /B 4 C green bodies at 1750°C for 2 h in a flowing argon atmosphere under ambient pressure without addition of pore‐forming agent. Using this new and simple method, the porosity and volume shrinkage of porous YbB 6 ceramics are controllable by changing the green density. The prepared porous YbB 6 ceramic has homogeneous pore structure with very narrow pore diameter distribution. Furthermore, the porous YbB 6 possesses high compressive strength of ~21.34 MPa when the porosity is ~58.7% and the density is ~2.27 g/cm 3 . The combination of these favorable properties renders porous YbB 6 ceramic being a light‐weight structural and functional component for UHT applications.