N the melt atomization process to make fine metal powders, there usually is a variation in powder size because not all atomized droplets are of the same size. In an experiment, it was found that titanium droplets of 10 μm dia reached their solidification temperature (1660 C) in 2 milliseconds when the surrounding gas temperature was 1100 C and the initial droplet temperature was 1860 C. How long would it take for droplets of 5 μm, 20 μm, 30 μm and 50 μm diameter to cool by the same amount if they all had the same initial temperature? Given: density of Ti = 4510 kg. m-3.