High-temperature flexural creep of ZrB2-SiC ceramics in argon atmosphere

Four-point flexure creep deformation of ZrB2-30 vol% SiC ceramics in argon atmosphere under a static load of 19 MPa for 0-100 h at 1500 and 1600 degrees C was investigated. The strain rate at 1600 degrees C was 3.7 times higher than that at 1500 degrees C. Microstructural evolution during creep consisted of nucleation and growth of triple-point cavitations which were always associated with SiC particles. Due to the low stress, only isolated cavitations were nucleated, and no microcracks were formed. For up to 100 h at 1500 and 1600 degrees C, the grains maintained their size and shape. The cavitations in both size and number showed no obvious difference from 26 to 100 h at 1500 degrees C, whereas that showed a significant increase from 26 to 100 h at 1600 degrees C. Present study suggested that ZrB2-30 vol% SiC exhibited relatively good microstructural stability and creep resistance at 1500 degrees C in argon atmosphere. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.