VEGA, L.E.R.LEIVA, D.R.LEAL NETO, R.M.SILVA, W.B.SILVA, R.A.ISHIKAWA, T.T.KIMINAMI, C.S.BOTTA, W.J.2020-04-072020-04-072020VEGA, L.E.R.; LEIVA, D.R.; LEAL NETO, R.M.; SILVA, W.B.; SILVA, R.A.; ISHIKAWA, T.T.; KIMINAMI, C.S.; BOTTA, W.J. Improved ball milling method for the synthesis of nanocrystalline TiFe compound ready to absorb hydrogen. <b>International Journal of Hydrogen Energy</b>, v. 45, n. 3, p. 2084-2093, 2020. DOI: <a href="https://dx.doi.org/10.1016/j.ijhydene.2019.11.035">10.1016/j.ijhydene.2019.11.035</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/31105.0360-3199http://repositorio.ipen.br/handle/123456789/31105In this study, we propose a method to produce nanocrystalline TiFe powder by high-energy ball milling, in order to avoid the common sticking problem of the material to the milling tools, assuring a material prompt to absorb hydrogen as well. The method consists of making a preliminary milling operation with the elemental powders (50:50 stoichiometric ratio) to form a strong adhered layer of the milled material on the surfaces of the vial and balls. The main milling operation is then performed with a new powder charge (same composition as before), but now adding a process control agent (stearic acid). Various processing times - 2, 6, 10 and 20 h - were used in the milling experiments. Nanocrystalline TiFe was synthesized in this way with low oxygen contamination, full yields for milling times of 6 h or over, requiring no heat treatments for the first hydrogen absorption. Hydrogen storage capacity of 1.0 wt% at room temperature under 20 bar was attained by the sample milled for 6 h. Kinetic data from samples milled for 2 h and 6 h agreed with Jander model for the rate limiting step of the hydriding reaction, which is based on diffusion with constant interface area.2084-2093openAccessintermetallic compoundsalloysmechanical propertiesnanocrystalsmillinghydrogen storagehydridesactivation analysisArtigo de periódico34510.1016/j.ijhydene.2019.11.0350000-0001-5104-7392https://orcid.org/0000-0001-5104-739269.7888.50