Fabrication of micro-fine high Nb-containing TiAl alloyed powders by fluidized bed jet milling

A fluidized bed jet milling process was used to make micro-fine high Nb-containing TiAl alloyed powders from the chippings obtained by crushing the Ti-45Al-8.5Nb-(W,B,Y) ingot. The influences of classifier frequency on powder characteristics were investigated. The results show that the powders with controlled average particle size can be prepared on a large scale. The powders with different sizes are all dominated by γ with a minor amount of α2-Ti3Al. The particle size significantly decreases with the classifier frequency increasing. At a classifier frequency higher than 38 Hz, the average particle size of the ground powders is lower than 25 μm. The powders are composed of two different sizes of particles: shaped particles and some clastic particles, and both particle sizes meet the log-normal distribution. With the classifier frequency increasing, the both sizes decrease; meanwhile, the proportion of the clastic particles gradually increases, and the size distribution span value of the ground powders increases correspondingly.