Effects of the speed ratio on the efficiency of planetary mills

C Real; F J Gotor

doi:10.1016/j.heliyon.2019.e01227

Effects of the speed ratio on the efficiency of planetary mills

Heliyon. 2019 Feb 15;5(2):e01227. doi: 10.1016/j.heliyon.2019.e01227. eCollection 2019 Feb.

Authors

C Real¹, F J Gotor¹

Affiliation

¹ Instituto de Ciencia de Materiales de Sevilla (US-CSIC), Américo Vespucio 49, 41092 Sevilla, Spain.

Abstract

The ignition time (t_ig) of the mechanically induced self-sustaining reaction (MSR) process involving the formation of TiB₂ from Ti/2B elemental mixtures was used to study the influence of the ratio (k = -ω _v /ω _d ) between the rotational speed of the supporting disc (ω _d ) and vials (ω _v ) on the milling efficiency of a Pulverisette 4 planetary mill. The variation of the inverse of the ignition time (1/t_ig), which is directly related to the milling power provided by the planetary mill, with the process conditions has shown that it is not possible to find a single k value as optimal independently of the experimental conditions used (ω _d and the ball-to-powder ratio, BPR). Moreover, it was observed that the lowest milling efficiency (longer t_ig values) was found for k = 1, which is the usual value employed in routine laboratory works. The best efficiencies were found for the larger k values (2.5 or 3). At lower ω _d, the shortest t_ig was obtained for k = 2.5 and at higher ω _d for k = 3, independently of BPR.

Keywords: Materials science.