The Peculiarities of Structure Formation Upon Sintering of TiH₂+TiB₂ Powder Blends

Abstract

The investigation results on peculiarities of phase and structure formation as well as sintering kinetic of compacted TiH2 - TiВ2 powder blends. It was shown, the most intensive shrinkage upon heating took place within temperature range of TiH2 dehydrogenation (400 ÷ 650 0С). Heating of powder blend up to sintering temperature (1350 0С) resulted in formation of acicular TiB particles in titanium matrix, the amount of particles is increased with increase in exposure to 20 min. The longer duration of isothermal exposure did not lead to increase in amount and size growing of TiB particles. X-ray analysis of sintered TiН2+TiВ2 powder blend demonstrated the presence of titanium matrix phase, orthorhombic TiВ phase, and traces of Ti-B compounds of different concentrations (Ті3В4 and Ті2В5). The dilatometric investigations proved that addition of boride compounds and increase in boride content in powder blend led to decrease in shrinkage upon sintering as compared to shrinkage of single TiH2 powder compacts. Key words: titanium, boride, hydride, sintering, structure, powder, dehydrogenation, metal matrix composite, powder blend.