Low porosity TiB2-SiC ceramics were prepared by Cold Isostatic Pressing-Pressureless Sintering (CIP-PS). The crack-healing behavior of these ceramics was investigated by pre-oxidizing the samples at 800-1200 degrees C in air for various durations ranging from 5 to 240 min. The effects of pre-oxidation temperature and time on the microstructure and mechanical properties of porous TiB2-SiC ceramics were studied. The strength of porous ceramics obviously improved after pre-oxidation, with a maximum increase in strength of 134.4% for samples pre-oxidized at 1200 degrees C for 120 min. The strengthening mechanism of porous TiB2-SiC ceramics after pre-oxidation was also investigated and discussed. This study provides a novel concept for improving the strength and structural integrity of porous ceramics in practical applications. (C) 2015 Elsevier B.V. All rights reserved.