Fe-Cu-Nb-Si-B快淬带的组织、磁性及微区力学性能

采用单辊熔体快淬法制备宽6~8mm、厚30~40μ_m的Fe_78.3Cu_0.6Nb_2.6Si_9.5B₉合金薄带.其直流磁性能为:饱和磁感应强度B_s=1.06T，剩磁B_r=0.39T，矫顽力H_c=3.53A/m，最大磁导率μ_m=2.43mH/m；交流磁性能为:铁损P_0.5T/1kHz=22.2W/kg，P_0.2T/100kHz=864W/kg，对应的有效磁导率μe分别为833和1225.场发射高分辨扫描电镜观察发现，不同工艺参数制备的快淬带因晶化程度不同，对应的断口形貌特点也不同，非晶相和纳米晶复合的合金带断口可见镜面区和雾状区、周期性褶皱、河流状花样等，而晶化接近完全的合金带呈沿晶断裂.纳米力学探针研究表明，非晶相和纳米晶复合的合金带的微区硬度和弹性模量低于晶化接近完全的合金带.基于Luborsky法，利用自行设计的装置测量断裂应变，对材料的韧性进行半定量分析. 

Microstructure,magnetic and micromechanical properties of Fe-Cu-Nb-Si-B melt-spun ribbons

Fe_78.3Cu_0.6Nb_2.6Si_9.5B₉ melt-spun ribbons of 6-8 mm in width and 30-40 μ_m in thickness were produced by using a single roller melt spinning technique machine. The melt-spun ribbons have the direct current (DC) magnetic properties of saturation flux B_s=1.06 T, remanence B_r=0.39 T, coercivity H_c=3.53 A·m-1 and maximum permeability μ_m=2.43 mH·m-1 and the alternating current magnetic properties of core loss P_{0.5 T/1 kHz}=22.2 W·kg-1, P_{0.2 T/100 kHz}=864 W·kg-1 and corresponding efficient magnetic permeability μ_e=833 and 1225. Field emission high resolution scanning electron microscopy results indicate that the melt-spun ribbons prepared at different technical parameters show different crystallization degrees and fracture morphology characteristics. The fracture surface morphology of the amorphous-nanocrystallized ribbons is composed of a mirror zone, a mist zone, a hackle zone, and a river-pattern zone, while the crystallized ribbons exhibit intergranular embrittlement. The microhardness and elastic modulus of the amorphous-nanocrystallized ribbons measured with a nano-indenter probe are lower than those of the crystallized ribbons. The fracture toughness of the melt-spun ribbons was semi-quantitatively determined by using a self-designed gauge based on the Luborsky method.