Effect of boron on crystallization process, forming ability and magnetic properties of amorphous Fe91-xZr5BxNb4 alloy

Abstract

Effects of boron (B) on crystallization, glass forming ability (GFA) and magnetic properties of amorphous Fe91-xZr5BxNb4 (FZBN) were studied in the B content ranging from 0 to 36 at%. The amorphous FZBN crystallizes to α-Fe in primary crystallization mode at B≤ 20 at% and to Fe-Zr-B-Nb cubic phase with lattice constant of 1.0704 nm and α-Fe in eutectic mode in the range from 22 at% to 30 at% B. The change of crystallization mode is accompanied by the sharp enhance of glass transition and crystallization temperatures. The GFA of FZBN alloys changes with B content and reaches the largest near 27.5 at % B. Curie temperature (Tc) and magnetization at room-temperature (MRT) and 78K (M78K) for the amorphous FZBN increase with increasing B content. However, the change laws of the Tc and the magnetizations are somewhat different in the composition ranges of 5 to 20 at% B and 22.5 at% to 30 at% B.