| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1618860 | Journal of Alloys and Compounds | 2011 | 7 Pages |
SiC-TiB2 particulate composites were fabricated by converting TiO2 to TiB2 through the reaction between TiO2, B4C and C. The presence of initially very fine, in-situ created, TiB2 particles increased driving force for sintering and enabled fabrication of a dense composite utilizing pressureless sintering and the liquid phase created between Al2O3 and Y2O3 additives. The effect of volume fraction of the in-situ formed TiB2 on density, microstructure and flexural strength was discussed. It was found that the presence of TiB2 particles suppressed the growth of SiC grains and enhanced fracture strength. The fracture strength of samples containing 12 vol% TiB2 was more than 30% higher than that of the monolithic SiC. The effect of SiC grain size on fracture strength was also analyzed.
Research highlights▶ The internal synthesis of TiB2 utilizing TiO2, B4C and C was found to be an effective way of producing dense SiC-TiB2 composites with high strength. ▶ The presence of TiB2 particles inhibits SiC grain growth and improves strength of samples containing up to 24 vol% TiB2. ▶ The reduction in strength of samples containing above 24 vol% TiB2 is attributed to an increase in porosity. ▶ Despite the lower inherent hardness of TiB2, the samples with up to 24 vol% TiB2 have hardness close to that of monolithic SiC.
