Corrosion behavior and phase formation of LaFe13 − xSixBy alloys

Abstract The co-influence of B and Si on the formation of 1:13 phase and corrosion behavior of LaFe 13 − x Si x B y alloys is investigated. 1:13 phase is found in as-cast LaFe 11.6 Si 1.4 B 0.5 , while there is no 1:13 phase in as-cast LaFe 12.0 Si 1.0 B 0.5 with lower Si content. The addition of B in the LaFe 13 − x Si x B y alloys is not helpful for the formation of 1:13 phase during the annealing process. B element prefers to form Fe 2 B, rather than occupying interstitial sites in the crystal structure of 1:13 phase, which results in the decrease of the value of magnetic entropy change (| Δ S  |). Corrosion behaviors of annealed LaFe 11.6 Si 1.4 B y alloys are reported. The results show that the addition of B improves the corrosion resistance of the alloys. Polarization curves of single phase α -Fe, Fe 2 B and 1:13 phase show that the potential difference between Fe 2 B and 1:13 phase is lower than that between α -Fe and 1:13 phase, which lead to the enhancement of corrosion resistance. The corrosion of LaFe 11.6 Si 1.4 B 0.3 is effectively suppressed, and the value of | Δ S  | is only reduced by 28%.