The comprehensive study on texture evolution and recrystallization behavior of twin-roll strip casting Fe-50 %Co alloy

Abstract

The iron-cobalt soft magnetic alloy exhibits excellent properties such as high saturation magnetic induction, high magnetic permeability, and high Curie temperature, making it widely used in areas like aviation generators and electric motors. However, traditional iron-cobalt alloy strip materials often suffer from a high magnetic anisotropy constant, which hinders their performance in practical applications. In this study, twin-roll strip casting was employed to produce Fe-50Co soft magnetic alloy cold-rolled strip materials. The research findings reveal that the initial microstructure of the Fe-50Co alloy strip prepared through twin-roll strip casting is primarily composed of coarse columnar grains and equiaxed grains, with a strong {001} orientation for the columnar grains. Notably, a significant number of Σ3 grain boundaries are present within the cast strip. These grain boundaries effectively reduce dislocation accumulation during the cold rolling process and subsequently minimize the nucleation sites for γ-texture during subsequent annealing. Furthermore, a strong {001}<uv0> texture is formed in the finished strip material after cold rolling and annealing, resulting in superior magnetic properties. The alloy exhibited excellent magnetic properties after annealing at 900 ℃ for 5 h followed by furnace cooling to 750 ℃ with the cooling rate of 50 ℃/h and then to 300 ℃ with the cooling rate of 180 ℃/h, the B5000 was ∼ 2.417 T, P1.5/400 was ∼22.651 W/kg and P2/1000 was 183.51 W/kg. These findings provide valuable insights for the development of Fe-50Co alloys with excellent magnetic properties.