| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1614066 | Journal of Alloys and Compounds | 2013 | 5 Pages |
•Hydrogen permeation in Nb–TiFe alloys is investigated.•The TiFe + (Nb, Ti) eutectic structure is obtained in the Nb16Ti53Fe31 alloy in the as-cast state.•Hydrogen permeable alloys consist of the primary TiFe phase and the eutectic structure.•Hydrogen permeation performance is increased with Nb content.
The relationship between the microstructure and hydrogen permeability of Nb–TiFe alloys is investigated. The fully eutectic alloy, which consisted of the bcc-(Nb, Ti) and B2-TiFe phases, is found in the Nb16Ti53Fe31 composition. The alloys formed between the Fe50Ti50 and Nb16Ti53Fe31 compositions, expressed as (Ti50Fe50)1−x(Nb16Ti53Fe31)x, consist of the eutectic structure, including the primary TiFe phase for x < 1 or the primary (Nb, Ti) phase for x > 1. The volume fraction of the primary phase is decreased (0 < x < 1) and increased (x > 1) with increasing x. The alloys with 0.4 < x < 0.8 are hydrogen permeable at 673 K. The Nb12Ti52Fe36 alloy with 60 vol% of the primary FeTi phase exhibits a high hydrogen permeability of 2.9 × 10−8 molH2/m/s/Pa0.5 at 673 K without hydrogen embrittlement. The formation of hydrogen permeable Nb–TiFe alloys is possible at higher Ti content and lower Nb content than those of the Nb–TiNi and Nb–TiCo alloys.
