Influence of P and C co-alloying on soft magnetic properties and crystallization behavior of FeSiBPCCu nanocrystalline alloys
Lei Xie, Qiang Li, Chuntao Chang, Xueru Fan, Aina He, Yuanfei Cai, Yaqiang Dong
Abstract
In this study, multicomponent synergistic effects were adopted to enhance the glass-forming ability (GFA), processing window (PW), thermal stability, and soft magnetic properties (SMPs) of FeCuSiB nanocrystalline alloys (NAs) with high Fe and Cu contents via P and C co-alloying. The co-addition of P and C is beneficial for enhancing the GFA, expanding the PW, and increasing the crystallization resistance of the compound phases in present FeCuSiBPC alloys. Consequently, the Fe 81.5 Cu 1.7 Si 3.8 B 9 P 3 C 1 alloy exhibited a large optimum T A window of up to 100 °C and a large t A window of 40 min for nanocrystallization. Crystallization kinetic analysis showed that the co-addition of P and C led to a high-frequency factor ( v ) in the precipitation of α-Fe crystals, which was related to the high nanocrystal density ( N d ) of α-Fe. This result may be attributed to the nucleation of α-Fe by Cu and CuP clusters. Additionally, the co-addition of P and C increased the growth active energy ( E p ) of the α-Fe crystals because of their larger atomic diffusion resistance. The high N d and E p values led to the formation of fine nanostructures and excellent SMPs in FeCuSiBPC alloys. Therefore, the Fe 81.5 Cu 1.7 Si 3.8 B 9 P 3 C 1 NA obtained by annealing at 420 °C for 30 min exhibited excellent SMPs with a B s of up to 1.78 T, a low H c of 7.5 A/m, and a high μ e of 9863 (@1kHz). This study provides technical and theoretical guidance for optimizing the composition and processability of NAs with high Fe and Cu contents, paving the way for mass production of high-performance soft magnetic NAs.