Hydrogenation of TiFe by high-energy ball milling

The hydrogenation properties of TiFe, TiFe 2 and pure Ti during high-energy ball milling in hydrogen atmosphere were studied. By ball milling, TiFe could absorb hydrogen without activation treatment. For Ti powder, a single phase TiH 1.924 was formed. In addition, TiFe 2 could also be hydrided by ball milling in hydrogen, which was ascribed to decomposition to form TiFeH x , TiH 1.924, and Fe. Based on the hydrogenation properties of Ti, TiFe, and TiFe 2 during dynamic ball milling and the thermal stability of the milled powders, it is proposed that the reactions in the milling of TiFe in hydrogen involve four steps: (1) fresh surfaces created by collision with the balls; (2) absorption of hydrogen by the powder; (3) oversaturation of hydrogen in the powder; (4) decomposition of TiFeH x to TiH 1.924 and Fe.