Characteristics of the milling of titanium carbide-iron powder mixtures with steel balls

Abstract

The processes of comminution of WC--Co [i] and TiC--Ni--Mo [2] hard-metal mixtures and titanium carbide--steel powder mixtures [3, 4] in revolving ball mills have already been investigated in some detail. From the literature it is known that the comminution of such mixtures is performed mainly in ball mills lined with a hard metal (in order to increase the wear resistance of the milling unit), using hard-metal balls made as a rule of VK grade (WC + Co) alloys as milling elements. However, titanium carbide hard-metal mixtures comminuted in such mills may pick up tungsten and cobalt. The lining and balls could, of course, be of the same alloy as the mixture being milled. However, titanium carbide alloy balls have a low density (~5.5.10 s as against ~14.5"i03 kg/m 3 for tungsten carbide balls), and consequently their kinetic energy is smaller and the milling process will be less effective.