Engineering and Technology Journal

Abstract

The research includes a study for the variables of the process of centrifugal
atomization for the purpose of producing pure tin metal powder and the effect of
these variables in the properties of the resulting powder. These variables are:
1. The speed of rotation in the rotating part.
2. The medium of cooling.
3. The temperature of medium of cooling.
The affect of these above variables were observed on the size and the shape of
particles resulting and the particle distribution, the apparent density, tap density and
the angle of repose.
Upon the use of three different speeds (2000, 6000, 10000) (rpm) on the each at a
time for the rotating of the hollow bowl and the use of water at the room temperature.
It was noticed that when increasing of revolution speed, there is no change in the
shapes of particles i.e. the wide extent of shapes remain irregular, acicular and
semispherical, and that the weight percentage of the small particles increases. Also,
the value of the apparent density and the tap density increases while the angle of
repose decreases.
It was also observed that at the use of air and water separately at the room
temperature as cooling media and disintegration the fused droplets of tin metal out of
the hollow bowl at rotation speed of (10000) rpm. Moreover, we can notice that the
weight percentage of the small particles increases as well as the value of the apparent
density and tap density, while the value of the repose angle decreases , and the
absence of any change in the shape of the particles when using water as a medium of
cooling , compare with air . A great range of irregular, acicular and semispherical
shapes are also obtained.
Water of different temperatures
({40-50}, {60-70}, {80-90})◦ C were was used as a cooling medium and for the
disintegrating of the droplets of the tin metal from the hollow bowl at rotation speed
of (10000) rpm, and the formation of powder of different sizes and shapes. Also, the
tendency of the particles towards regularity of shape and the spherical shape clearly
with the decrease of the weight percentage of the small particles , and the value of
apparent density and the tap density increase and the value of the angle of repose
decreases at the increase of the temperature of water cooling medium.