FeCuNbSiB纳米晶软磁粉芯的制备和磁性能

Fabrication and Magnetic Properties of FINEMET Alloy Powder Cores

采用熔体快淬法制备了Fe73.5Cu1Nb3Si13.5B9（FINEMET,at%）非晶薄带,通过高能球磨制成磁粉,筛分后的磁粉在0.2%~1.0%（质量分数）的磷酸溶液中钝化,并与0.4%的环氧树脂混合,于1.64~1.96 GPa下压制成磁环。磁环经过500℃去应力退火处理,在非晶基体表面析出晶粒大小为14.3 nm的纳米晶α-Fe（Si）相。通过去应力过程和双相结构的协同作用,纳米晶软磁粉芯表现出优良的磁性能,在100 kHz和0.1 T下的损耗仅为583 mW/cm3。

Melt-spun amorphous Fe73.5Cu1Nb3Si13.5B9 （FINEMET, at%） ribbons were ball-milled to obtain powder. The powder was sieved and then passivated in 0.2-1.0% phosphoric acid solution to form a well-coated passivator layer, followed by cold compaction under the pressure of 1.64-1.96 GPa to prepare toroidal magnetic cores. The powder cores were annealed at 400-600 ℃ to relieve the internal stress and to optimize the crystalline grain size. After annealed at 500 ℃ for 1 h, a-Fe（Si） crystallites with an average grain size of 14.3 nm were embedded in the amorphous matrix. Combined with the insulation of each powder and the two-phase structure, the powder core exhibits excellent magnetic properties.