Abstract
An analytical approach was developed to investigate nucleation, recalescence and growth of Ti-48Al (at.%) alloy droplets during their flight in a gas atomization process. Evolution of microstructure of the solidified powders was quantitatively investigated using scanning electron microscopy, transmission electron microscopy and electron back-scatter diffraction. Relationships among the initial number of nuclei, liquid/solid interface velocity and cooling rate have been established. Results showed that statistical nucleation events increased exponentially with increasing droplet size, and the powder microstructures were transformed from a twinned spherical segment into a concentric liquid/solid interface geometry. Variations of initial temperature, cooling rate and solid fraction of the droplets as a function of cooling durations for the droplets with various sizes were investigated.
Original language | English |
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Pages (from-to) | 603-610 |
Journal | Nanoscience and Nanotechnology Letters |
Volume | 7 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2015 |
Keywords
- Gas Atomization
- microstructure
- TiAl Alloy
- nucleation
- cooling rate