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The Scientific World Journal
Volume 2014, Article ID 419386, 11 pages
http://dx.doi.org/10.1155/2014/419386
Research Article

Effect of Repeated Thermal Shock on Mechanical Properties of ZrB2-SiC-BN Ceramic Composites

1Applied Science Academy, Harbin University of Science and Technology, Harbin 150001, China
2Beijing Institute of Aerospace Systems Engineering, Beijing 100076, China

Received 11 August 2013; Accepted 4 November 2013; Published 16 January 2014

Academic Editors: F. Oktar and B. C. Ray

Copyright © 2014 Gang Li and Hongbo Chen. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

ZrB2-20 vol.% SiC-10 vol.% h-BN (particles) ceramic composites (ZSB) were fabricated by hot pressing under inert gas protected. ZSB samples with mean size 75 × 55 × 40 mm3 were heated using current heating method and then cooled down to low temperature by circulating water. ZSB samples repeatedly went through thermal shock with 10–50 times under various conditions, respectively. Diverse effects on residual strength of ZSB at different experiment conditions (temperatures, thermal shock times, and heating rates) were investigated. The test results indicated that the residual strength of specimen materials all reached the maximum while the temperature was 1600°C and thermal shock number was less than 50 times. Because ZSB samples could not stand the extremely serious hyperoxidation at very high temperature (1800°C), the residual strength of samples decreased sharply. At 1600°C, when the thermal shock times was 20, ZSB samples’ residual strength reached the maximum, but it decreased to the lowest point while the thermal shock times was 30. So we argued that the sensitive thermal shock number was 30. Finally, we analyzed the influences on samples residual strength generated by different heating rates at the same temperature and thermal shock number; the results showed that when heating rate was equal to cooling rate, the residual strength of specimen materials reached the maximum.