Effect of nano-ZrO₂ on microstructure and thermal shock behaviour of Al₂O₃/SiC composite ceramics used in solar thermal power

Abstract

The Al₂O₃-ZrO₂(3Y)-SiC composite ceramics used in solar thermal power were prepared by micrometric Al₂O₃, nano-ZrO₂ and SiC powders under the condition of pressureless sintering. The bulk density and bending strength of samples with 10vol% nano-ZrO₂ sintered at 1480 °C were 3.222 g/cm³ and 160.4 MPa, respectively. The bending strength of samples after 7 times thermal shock tests (quenching from 1000 °C to 25 °C in air medium) is 132.0 MPa, loss rate of bending strength is only 17%. The effect of nano-ZrO₂ content on the microstructure and performance of Al₂O₃-ZrO₂(3Y)-SiC composite ceramic was investigated. The experimental results show that the bending strength of samples with above 10vol% nano-ZrO₂ content has decreased, because the volume expansion resulting from t-ZrO₂ to m-ZrO₂ phase transformation is excessive; Adding proper nano-ZrO₂ would be contributed to improve the thermal shock resistance of the composite ceramics. The Al₂O₃-ZrO₂(3Y)-SiC composite ceramic has promising potential application in solar thermal power.

Keywords

Al₂O₃ / nano-ZrO₂ / transformation toughening / thermal shock resistance / composite ceramics / solar thermal power

References

[1] Koji T., Masahiro Y., Sangkee L., . Crack-healing Behavior of Al₂O₃ Toughened by SiC Whiskers[J]. J. Am. Ceram. Soc., 2003, 86(12): 2143-2147.

[2] Fayette S., Smith D. S., Smith A., . Influence of Grain Size on the Thermal Conductivity of tin Oxide Ceramics[J]. J. Eue. Ceram. Soc., 2000, 20: 297-302.

[3] Ebrabimi M. E., Chevalier J., Fantozzi G. Slow Crack Growth Behavior of Alumina Ceramics[J]. J. Mater. Res., 2000, 15(1): 142-147.

[4] Hirata T., Katsnnori A., Yamamotto H. Sintering Behavior of Cr₂O₃-Al₂O₃ Ceramics[J]. J. Eur. Ceram. Soc., 2000, 20: 195-199.

[5] Niihara K. New Design Concept of Structural Ceramics[J]. J. Ceram. Soc. Jpn., 1991, 99(10): 974-982.

[6] Zhao J., Stearns L. C., Hammer M. P., . Mechanical Behavious of Alumina-silicon Carbide Nanocomposites[J]. J. Am. Ceram. Soc., 1993, 76(2): 503-510.

[7] Davidge R. W., Brook R. J., Cambier J., . Fabrication Properties and Modelling of Engineering Ceramics Reinforced with Nanopaticles of Silicon Carbide[J]. Br. Ceram. Traus., 1997, 96(3): 121-127.

[8] Baron B., Klmar C. S., Gonidec L. Comparion of Different Alumina Powders for the Aqueous Processing and Pressureless Sintering of Al₂O₃-SiC Nanocomposites[J]. J. Eur. Ceram. Soc., 2002, 22: 1543-1552.

[9] Galesek D., Sedlacek J., Riedel R. Al₂O₃-SiC Composites Prepared by Warm Pressing and Sintering of an Organosilicon Polymer-coated Alumina Powder[J]. J. Eur. Ceram. Soc., 2007, 27: 2385-2392.

[10] Yoshida H., Okada K., Ikuhara Y., . Improvement of High-temperature Creep Resistance in Fine-grained Al₂O₃ by Zr⁴⁺ Segregation in Grain Boundaries[J]. Philos.. Mag. Lett., 1997, 76(1): 9-14.

[11] Wakai F., Nagano T., Iga T. Hardening in Creep of Alumina by Zirconium Segregation at the Grain Boundary[J]. J. Am. Ceram. Soc., 1997, 80(9): 2361-2366.

[12] Wang C. M., Cargill G. S. III, Harmer M. P., . Atomic Structural Environment of Grain-boundary-segregated Y and Zr in Creep-resistant Alumina From EXAFS[J]. Acta. Mater., 1999, 47(12): 3411-3422.

[13] Takigawa Y., Ikuhara Y., Sakuma T. Grain Boundary Bonding State and Fracture Energy in Small Amount of Oxide-doped Fine-grained Al₂O₃[J]. J. Mater. Sci., 1999, 34: 1991-1997.

[14] Deng Z. Y., Xu F. F., She J. S., . Effects of Zirconium Doping on Grain-boundary Bonding in Alumina-silicon Carbide Composites [J]. J. Am. Ceram. Soc., 2004, 87(3): 493-495.

[15] Szutkowska M., Boniecki M. Subcritical Crack Growth in Zirconia-toughened Alumina (ZTA) Ceramics[J]. J. Mater. Proc. Tech., 2006, 175: 416-420.

[16] Bartolome J. F., Bruno G., Deaza A. H. Neutron Diffraction Residual Stress Analysis of Zirconia Toughened Alumina (ZTA) Composites[J]. J. Eur. Ceram. Soc., 2008, 28(9): 1809-1814.

[17] Lange F. F. Transformation Toughening. Part 2: Contribution to Fracture Toughness[J]. J. Mater. Sci., 1982, 17: 235-239.

[18] Lin G. Y., Lei T. C. Microstructure, Mechanical Properties and Thermal Shock Behaviour of Al₂O₃+ZrO₂+SiC_w Composites[J]. Ceram. Int., 1998, 24: 313-326.

[19] Srdic V. V., Radonjic L. Transformation Toughening in Sol-gel-derived Alumina-zirconia Composites[J]. J. Am. Ceram. Soc., 1997, 80(8): 2056-2060.

[20] Sarkar D., Adak S., Chu M. C., . Influence of ZrO₂ on the Thermo-mechanical Response of Nano-ZTA[J]. Ceram. Int., 2007, 33: 255-261.