If you use SS then definitely the difference in the hardness values cause a lot of wear in jar (means contamination in alumina powder), so I feel that agate is a better option.

~300rpm would be better.

Thanks for your answer, do you have any kind of reference or paper in that regard that I can proof that with my supervisor?

Thanks

Ardalan

You may want to check: https://www.researchgate.net/post/How_to_decrease_particle_size_of_alumina_powder_with_ball_milling

Thanks Carlos Queiroz for referring.

Hi Nasiri,

You can search some research articles and books by LB Kong, BS Murty (IIT Madras, India also working on related materials, https://mme.iitm.ac.in/murty/home) and SV Suryanarayana and some other . They have been given wide report on your topics. They might be quite useful to you. I wish you good luck.