Ultra-high elevated temperature strength of TiB2-based ceramics consolidated by spark plasma sintering

Abstract

Spark plasma sintering of TiB2–boron ceramics using commercially available raw powders is reported. The B4C phase developed during reaction-driven consolidation at 1900°C. The newly formed grains were located at the grain junctions and the triple point of TiB2 grains, forming a covalent and stiff skeleton of B4C. The flexural strength of the TiB2–10wt.% boron ceramic composites reached 910MPa at room temperature and 1105MPa at 1600°С. Which is the highest strength reported for non-oxide ceramics at 1600°C. This was followed by a rapid decrease at 1800°C to 480–620MPa, which was confirmed by increased number of cavitated titanium diboride grains observed after flexural strength tests.