Preparation of activated nano anatase/ carbon powders by high-energy mechanical milling

Activated anatase/ carbon powders are excellent precursors for the synthesis of Ti(C, N) through the carbothermal reduction-nitridation (CRN) method, because the activated powders can facilitate the CRN to progress at lower temperature and shorter time. In this study, activated nano anatase/ carbon powders were successfully prepared by high-energy mechanical milling. The influences of some milling factors, such as milling time and speed, ball-to-powder weight ratio, carbon source and control agent on the activated powders were discussed in detail. The results show that high-energy mechanical milling can lead to a homogeneous blend of the starting powders at nanostructural level. However, the conversion of anatase from crystalline phase to amorphous phase was not obvious during milling. Furthermore, polymorphic transformation of anatase to srilankite or rutile did not occur in all the milling experiments conducted. Based on the current study, the appropriate milling parameters have been determined as follows: milling time of 4-8 h, ball-to-powder weight ratio of 15:1-30: 1, and milling speed of 400-700 rpm.