Titanium Grade 2 was processed by cryogenic milling and subsequently sintered by field assisted sintering technique (FAST) with the aim of creating and preserving the ultra-fine grained microstructure. Microstructural investigation was performed after both milling and sintering, a transmission Kikuchi diffraction was used to characterize the individual milled powder particles.
The milled powders showed significant grain refinement down to 50 nm. We assume this to be the equilibrium grain size resulting from the balance of deformation, recovery and dynamic recrystallization.
A rolling-like texture was also found in the milled particles as a result of the deformation mechanism during milling. The grain size of the sintered samples ranged from 0.5 to 10 μm, depending on the sintering conditions.
Although the grains are completely recrystallized, a texture similar to the powder was also found in these samples as a result of packing of the powder particles and continuous static recrystallization.