REACTION SYNTHESIS/DYNAMIC COMPACTION OF TITANIUM CARBIDE AND TITANIUM DIBORIDE

摘要

Titanium carbide and titanium diboride were synthesized by self-propagating combustion reactions and densified by a high-speed forging technique, in which a hammer strikes the hot and porous ceramic ([MATH]) at velocities in the range 5 - 15 m/s. Compacts with densities higher than 96% of the theoretical density and diameters close to 10 cm were produced by this method. Optical and scanning electron microscopy of the consolidated material were carried out, revealing a grain size of approximately 44 µm for TiC and 15 µm for TiB2 ; these grains were equiaxed, indicating that crystallization (or recrystallization) occurred after the densification process. The quasistatic and dynamic compressive strengths were established and compared to those of hot-pressed material produced by CERCOM. For TiB2, the strengths were approximately 1.8 GPa, while for TiC the quasistatic (10-3 s-1) and dynamic (102 s-1) strengths were 1.7 and 2.2 GPa, respectively.