Hafnium carbide and boride- based materials withstanding temperature in excess of 2000°C

Hf-borides and carbides are ultra-refractory due to their melting points above 3200°C and their excellent thermal stability. These materials are considered very promising for their use as thermal protection barriers for the space vehicle during the re-entry in the atmosphere. A new process for the production of high density borides and carbides has been set up using pressureless sintering, that allows the production of complex shapes. The tests to evaluate the behaviour of these ceramics under conditions simulating those typical of the re-entry stage are carried out in a plasma wind tunnel at temperatures higher than 2000°C: these materials exhibit excellent behaviours and very low surface degradation.