Hi

Chances of hitting will improves when using small balls and bigger one...

Best

Arunprakash Vincent

Better packing factor can be achieved when a mixture of different sizes of balls are used that in turn could help enhance the impact energy transfer between the ball and particle. Finer particle size is possible for a fixed ball to powder ratio when you compare the results between similar ball size and mixed sizes.

Thanks Krishnan Raja sir and Arun Prakash sir for your valuable information. I have one more clarification needed sir. I did literature survey on Planetary ball mill (especially Wet milling). In that wet milling process Why they are using toluene or steric acid as a process control agent sir.

The size of ball mill used will affect the sizes of the particle produced. In addition to this the time of milling is also an important factor to consider. In some cases of wet milling, solvent is added to enhance the breaking down of the materials and to lubricate the passage used.

If the ball milling is not carried out under a cover of an inert gas such as argon, the metal/alloy or non-oxide ceramic particles could easily oxidize. The frictional heat accelerates the oxidation process. To prevent or control the surface oxidation of the particles, inert (aprotic and non-polar) organic liquid such as hexane or toluene is added. This will be adsorbed on the surface of the particles and prevent oxidation. Vapor of the organic liquid will also help purge out the air in the container. Adsorption of organic species will decrease the surface energy of the particles and help easy fragmentation, as pointed out by O.D. Adeniyi in the earlier response. Stearate is a lubricant. It prevents sticking of the particles and also reduce the frictional heat. The organic additives may increase the carbon content of the material being milled.

Thanks to O.D.Adeniyi sir and Krishnan Raja sir for your valuable information.