Mechanical behavior of zirconium diboride–silicon carbide–boron carbide ceramics up to 2200 °C. Issue 2 (February 2015)

• Record Type: Journal Article
• Authors: Neuman, Eric W.; Hilmas, Gregory E.; Fahrenholtz, William G.
• Is Part Of: Journal of the European Ceramic Society. Volume 35:Issue 2(2015:Feb.)
• Page Start: 463
• Page End: 476
• Publication Date: 2015-02
• 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.2014.09.021
• Languages: English
• ISSNs: 0955-2219

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <p id="spar0005">The mechanical properties of hot pressed zirconium diboride–silicon carbide–boron carbide (ZrB₂–SiC–B₄C) ceramics were characterized from room temperature up to 2200 °C in an argon atmosphere. The average ZrB₂ grain size was 3.0 μm. The SiC particles segregated into clusters, and the largest clusters were &gt;30 μm in diameter. The room temperature flexural strength was 700 MPa, decreasing to 540 MPa at 1800 °C and to 260 MPa at 2200 °C. The strength was controlled by the SiC cluster size up to 1800 °C. At higher temperatures, strength was controlled by formation of liquid phases, and precipitation of large BN and B–O–C–N inclusions. The mechanical behavior of these materials changes at ∼1800 °C, meaning that extrapolation of properties from lower temperatures is not accurate. Mechanical behavior in the ultra-high temperature regime was dominated by impurities and changes in microstructure. Therefore, the use of higher purity materials could lead to significant improvements in ultra-high temperature strength.</p> </sec> </abstract>