Microstructures and Multi-Toughening of ZrO₂ Nano-Micron Fibers Self-Toughening Al₂O₃ Ceramics from In Situ Growth in the Melts Produced by Combustion Synthesis

Abstract:

Al2O3/24%ZrO2 composite, which is mainly composed of lath-shaped and rod-shaped α-Al2O3 matrix containing ZrO2 nano-micron fibers, was obtained from in-situ growth in the melts produced by combustion synthesis. The results from XRD, SEM and EPMA showed that, besides the rod-shaped and lath-shaped α-Al2O3 grains, there are also t-ZrO2 or m-ZrO2 independent phases and Cr metallic particles at the boundaries of rod-shaped grains. The strength and toughness were measured to be 1186 MPa and 12.8MPa·m0.5 respectively. The procedure for toughening ceramics relies on coordinated action of multiple toughening mechanisms involving reinforcement-induced toughening by ZrO2 nano-micron fibers, deflection-induced toughening, stress-induced transformation toughening, crack-bridging toughening by lath-shaped α-Al2O3 grains as well as deformation-induced toughening by Cr metallic particles, and promises the occurrence of a sharp rising R-curved behavior.

• Periodical: Key Engineering Materials (Volumes 336-338)
• Pages: 2257-2259
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.336-338.2257
• Online since: April 2007
• Authors: Long Zhang, Zhong Min Zhao, Jian Zheng, Hong Bai Bai, Jiang Wu
• Keywords: Composite Ceramic, In Situ Growth, Nano-Micron Fibers, Toughness

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