Effects of Sintering Temperature and Excess Zr on Mechanical Properties of Reactive Hot-Pressed ZrB₂-ZrC_x-Zr Cermets

Abstract:

In this study, a series of ZrB₂-ZrC_x-Zr cermets were prepared by reactive hot-pressing of Zr + B₄C powder mixtures at different temperatures between 1400°C and 1900°C. The microstructure of the resulting cermets was characterized by field emission scanning electron microscopy. The strength and fracture toughness of the cermets were measured by four-point bending test at room temperature. The results showed that the strength and fracture toughness dependend on the amount of excess Zr and sintering temperature as well. In addition, the crack propagation behavior of the cermets was examined under indent cracking. The cracks induced by indenter directly propagated in the samples with less than 16 vol% Zr. For comparison, the multiple cracking behavior was observed for the samples with equal to or greater than 16% Zr. Furthermore, the effects of compositions and sintering temperatures on the microstructure and the mechanical properties of the cermets were discussed.

• Periodical: Key Engineering Materials (Volume 697)
• Pages: 633-638
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.697.633
• Online since: July 2016
• Authors: S.Q. Guo
• Keywords: Cermet, Mechanical Behavior, Microstructure, Reactive Hot Pressing, Zirconium Compounds

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