Contact-mechanical properties at intermediate temperatures of ZrB2 ultra-high-temperature ceramics pressureless sintered with Mo, Ta, or Zr disilicides. Issue 11 (October 2015)

• Record Type: Journal Article
• Authors: Rodríguez-Sánchez, Jesús; Sánchez-González, Estíbaliz; Guiberteau, Fernando; Ortiz, Angel L.
• Is Part Of: Journal of the European Ceramic Society. Volume 35:Issue 11(2015:Nov.)
• Page Start: 3179
• Page End: 3185
• Publication Date: 2015-10
• Subjects: Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.04.023
• Languages: English
• ISSNs: 0955-2219

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <p id="spar0005">The elasto-plastic properties and contact damage evolution of ZrB₂ ultra-high-temperature ceramics (UHTCs) pressureless sintered at 1900 °C with MoSi₂, TaSi₂, or ZrSi₂ additive were evaluated by Hertzian indentation tests in air up to 800 °C. It was found that liquid-phase sintering occurred in the three cases, but with severe decomposition of the TaSi₂ and ZrSi₂ additives and extensive formation of (Zr_{1−<italic>m</italic>}Si_{<italic>m</italic>})B₂ solid-solutions in the case of the ZrSi₂ additive. Furthermore, ZrB₂ sintered with ZrSi₂ underwent severe peptization at 800 °C, raising questions as to its utility as a UHTC. It was also found that ZrB₂ sintered with MoSi₂ exhibits the best combination of contact-mechanical properties, being harder, stiffer, and more resistant to quasiplastic damage and radial cracking than ZrB₂ sintered with TaSi₂ or ZrSi₂, as well as equally resistant to ring/cone cracking from ∼600 °C onwards. Implications of interest for the UHTC community are discussed.</p> </sec> </abstract>