Mechanical Properties of Zirconium-Diboride Based UHTCs


This chapter discusses the current state-of-the-art in mechanical properties of zirconium diboride based Ultra-High temperature ceramics. The properties covered include the elastic modulus, strength, and fracture toughness at both ambient and elevated temperatures. The discussion concentrates on monolithic zirconium diboride, and zirconium diboride with additions of silicon carbide and/or transition metal disilicides as a second phase. The effect of microstructure and impurities on the mechanical properties will be discussed. An example is the finding that the morphology of the second phase, and its distribution, controls the mechanical properties of in ZrB2-based ceramics. The chapter will also discuss the improvements in mechanical properties that have been obtained using modern powders and processing techniques compared to historic studies from the 1960s. For example, an improvement in the strength of monolithic ZrB2 at 2200⁰C has recently been realized, from 50MPa for the historic material to 200MPa for the modern material. The chapter concludes with suggestions for improving the mechanical properties of diborides and recommendations for future studies.


Materials Science and Engineering

Keywords and Phrases

Elastic modulus; Hardness; Molybdenum disilicide; Silicon carbide; Strength; Toughness; Ultra-High temperature ceramics; Zirconium diboride

International Standard Book Number (ISBN)

978-1118700853; 978-1118700785

Document Type

Book - Chapter

Document Version


File Type





© 2014 Wiley Blackwell, All rights reserved.

Publication Date

01 Nov 2014