ZrB 2-based sponges and lightweight devices

This work deals with the production of zirconium diboride (ZrB2)-based ultra-high-temperature ceramic porous bodies using different forming techniques with the aim to obtain a reduction in weight of the final components, to balance the high specific mass of ZrB2, useful especially in aerospace applications. A feasibility study for the production of ZrB2-based porous bodies from sponges and foams was carried out. A ZrB2 composition, containing silicon carbide as the secondary phase and silicon nitride (Si3N4) as a sintering aid, has been chosen with the aim to obtain lightweight devices by the replica method through slip casting of ceramic suspensions. Moreover, ZrB2 macroporous materials have been successfully produced using Si3N4 as a sintering aid and ovalbumin as a foaming agent. Sintering was performed at 21501C with a dwell time of 120 min after a suitable process to pyrolize the organic templates and additives.