Effects of Ribbon Thickness on Structure and Soft Magnetic Properties of a High-Cu-Content FeBCuNb Nanocrystalline Alloy

• 作者: Li-Cheng Wu Yan-Hui Li Xing-Jie Jia Ai-Na He Wei Zhang
• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2022,（2）
• 页码范围: 235-242
• 页数: 8页
• 语种: 英文

摘要

The effects of ribbon thickness (t) on the structure and magnetic properties of a Fe82.3B13Cu1.7Nb3 alloy in melt-spun and annealed states have been investigated.Increasing the t from 15 to 23 lμm changes the structure of the melt-spun ribbons from a single amorphous phase to a composite with dense α-Fe nanograins embedded in the amorphous matrix.The grain size (Dα-Fe) of the α-Fe near the free surface of the ribbon is about 6.7 nm,and it gradually decreases along the cross sec-tion toward the wheel-contacted surface.Further increasing the t to 32 μm coarsens the Dα-Fe near the free surface to 15.2 nm and aggravates the Dα-Fe ramp along the cross section.After annealing,the ribbon with t=15 μm has relatively large α-Fe grains with Dα-Fe ＞ 30 nm,while the thicker ribbons possessing the pre-existing nanograins form a finer nanostructure with Dα-Fe ＜ 16 nm.The structural uniformity of the ribbon with t =23 μm is better than that of the ribbon with t =32 μm.The annealed ribbons with t=23 and 32 μm possess superior soft magnetic properties to the ribbon with t=15 μm.The ribbon with t=23 μm exhibits a high saturation magnetic flux density of 1.68 T,low coercivity of 9.6 A/m,and high effec-tive permeability at 1 kHz of 15,000.The ribbon with t=32 μm has a slightly larger coercivity due to the lower structural uniformity.The formation mechanism of the fine nanostructure for the ribbons with suitable t has been discussed in terms of the competitive growth effect among the pre-existing α-Fe nanograins.