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Indexed by:期刊论文

Date of Publication:2011-08-19

Journal:COMPOSITES SCIENCE AND TECHNOLOGY

Included Journals:SCIE、EI

Volume:71

Issue:12

Page Number:1501-1506

ISSN No.:0266-3538

Key Words:Ceramics; Strength; SEM

Abstract:The isothermal oxidation of the ZrB2-SiC-ZrC ceramic was carried out in static air at a constant temperature of 1000 +/- 15 degrees C, 1200 +/- 15 degrees C and 1400 +/- 15 degrees C for 30 min, respectively. Compared with the original strength of 580 MPa, the strength for the specimen oxidized at 1000 degrees C, 1200 degrees C and 1400 degrees C for 30 min increased to 609 MPa, 656 MPa and 660 MPa, respectively, because the flaws in the surface of the specimen were sealed by the oxide layer. The thermal shock resistance of the specimens before and after the oxidation was measured by the water quenching. The measured Delta T-crit for the specimen oxidized at 1000 degrees C, 1200 degrees C and 1400 degrees C were 352 degrees C, 453 degrees C and 623 degrees C, respectively, which was obviously higher than 270 degrees C for the unoxidized specimen. The improvement in the thermal shock resistance was attributed to the formation the oxide layer on the surface of the specimen. The results here pointed to a promising method for improving strength and thermal shock resistance of ZrB2-based ceramics. (C) 2011 Elsevier Ltd. All rights reserved.