退火对铁基超微晶软磁合金磁性能影响的研究

The Effect of Annealing on the Magnetic Properties of Fe-based Nanometer-sized Crystalline Soft Magnetic Alloys

本文研究了铁基超微晶软磁合金FeCuNbSiB的微观结构和磁性能的关系,试图揭示超微晶铁基合金取得优异软磁性的机制。用改变热处理条件的办法,在520～700℃之间对淬态非晶合金进行等温热处理后,均获得晶粒大小为10～40nm的主相为α-FeSi固溶体相的超微晶结构。处理温度在520-600℃之间的试样均具有优良的软磁特性,高于600℃样品磁性开始恶化。α-FeSi固溶体的晶粒尺寸在520～620℃之间等温退火后均无明显变化,最佳磁性能对应的退火温度范围与晶粒尺寸对应的温度范围并不相同,表明超微晶合金的磁性虽与晶粒尺寸密切相关,此外晶粒边界相也直接影响其磁性。

The relations betwsen magnetic properties and microstructure in Fe based nanometer-sized crystalline soft magnetic alloys is investigated to clarify the mechanism by which ultrafine cystalline alloys have excellent soft magnetic properties. Through changing annealing conditions, as-quenched amorphous alloy ribbons are annealed in constant temperature between 520℃ and 700℃ , ultrafine crystalline structure is obtaind by all samples.Their main phase is a-FeSi solid solution and their size of grain is 10nm-40nm. Th ; samples quenched between 520℃-600℃ have good soft magnet'c properties. The soft magnetic properties of samples quenched above 600℃ are deteriorated. The size of grains a-FeSi solution has not obvious change when the samples are annealed between 520℃-620℃. The annealing temperature ranges corresponding to optimum magnetic property and to unchanged grainsize are not same. It shows that ultrafine crystalline alloys' magnetic properties are interrelated with grain size, but grain boundary phase also influences alloys' magnetic propeties directly.