title: High-strength zirconium diboride-based ceramic composites consolidated by low-temperature hot pressing.
abstract: Two compositions of ZrB2-based ceramic composites containing Si3N4, Al2O3and Y2O3have been hot-pressed at different temperatures between 1673 and 1773 K for 60 min in vacuum. The densification behavior of the composites was examined during the sintering process. The microstructures of the composites were characterized by scanning electron microscopy, and the crystalline phases were identified by x-ray diffraction. The effects of Al2O3and Y2O3additives on the densification behavior and flexural strength were assessed. A relative density of ∼95% was obtained after sintering at 1723 K or higher temperatures. The microstructures of the composites consisted of (Zr,Y)B2,α-Si3N4and Y3(Al,Si)5O12phases. The room-temperature flexural strength increased with the amount of additives and approached 1 GPa.
authors.affiliation: Hybrid Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.
authors.forename: Shuqi
authors.initials: S
authors.lastname: Guo
authors.affiliation: Hybrid Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan; Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kagawa
keywords: high strength; low-temperature densification; oxide additives; silicon nitride; zirconium diboride