ZrB2-matrix composites, ultra-high temperature ceramics (UHTCs), mechanical properties, strengthening and toughening mechanism, oxidation behavior
Novel ZrB2-matrix composites were designed and prepared by in-situ introducing SiC and Zr2[Al(Si)]4C5 simultaneously for the first time. The obtained composites were dense and showed good mechanical properties, especially the strength and toughness, 706 MPa and 7.33 MPa·m1/2, respectively, coupled with high hardness of 21.3 GPa, and stiffness of 452 GPa. SiC and Zr2[Al(Si)]4C5 constituted a reinforcing system with synergistic effects including grain refinement, grain pull-out as well as crack branching, bridging, and deflection. Besides, the oxidation results of the composites showed that the oxidation kinetics followed the parabolic law at 1600 ℃, and the oxidation rate constants increased with the increase of Zr2[Al(Si)]4C5 content. The formation and evolution model of the oxidation structure was also investigated, and the oxide scale of the composite exhibited a three-layer structure.
YU, Lei; LIU, Hui; FU, Yaohui; HU, Weijiang; WANG, Zhefei; LIU, Quan; WEI, Bo; YANG, Jian; and QIU, Tai
"Design and preparation of an ultra-high temperature ceramic by in-situ introduction of Zr2[Al(Si)]4C5 into ZrB2-SiC: Investigation on the mechanical properties and oxidation behavior,"
Journal of Advanced Ceramics: Vol. 10:
5, Article 11.
Available at: https://dc.tsinghuajournals.com/journal-of-advanced-ceramics/vol10/iss5/11