X.J. Jia, Y.H. Li, L.C. Wu, W. Zhang. Journal of Alloys and Compounds, 2020, 822:152784.

Abstract:

Amorphous-forming ability (AFA) and thermal stability of melt-spun Fe_85-xNi_xSi₂B₈P₄Cu₁ (x = 0–20) alloys and their crystallized structure, magnetic and mechanical properties have been investigated. The increase of Ni content from 0 to 20 at.% gradually improves the AFA with enlarging the critical thickness for amorphous formation from 14 to 38 μm. Adding 5 at.% Ni increases the number density (N_d) of nucleation sites by properly delaying the Cu atoms clustering process during annealing and refines the α-(Fe, Ni) grains, which leads to a magnetic softness improvement of the nanocrystalline alloys. The excessive Ni (≥10 at.%) decreases the N_d due to the overinhibition of the Cu clustering, resulting in the grains coarsening and magnetic softness deterioration. The Fe₈₀Ni₅Si₂B₈P₄Cu₁ nanocrystalline alloy possesses finer α-(Fe, Ni) grains with an average size of 22 nm, a lower coercivity of 14.3 A/m and saturation magnetic flux density of 1.77 T as compared with those of 40 nm, 105.3 A/m and 1.84 T, respectively, for the Fe₈₅Si₂B₈P₄Cu₁ alloy. In addition, the nanocrystalline alloys with 2.5–10 at.% Ni show reduced brittleness compared with the Ni-free alloy owing to the grain refinement, and the alloys with 15–20 at.% Ni possess further decreased brittleness as a consequence of the reduced α-(Fe, Ni) phase volume fraction.

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