通过单辊快速凝固的方法制备出宽度为20 mm, 厚度为35－50 μm,连续成卷的Fe－6.5%Si合金薄带. 与普通铸造方法相比,用快速凝固方法得到的Fe－6.5%Si合金具有良好的室温塑性.采用TEM及XRD研究了普通铸锭和快凝薄带的有序化结构和微观组织,并计算了这2种制备条件下B2有序相的长程有序度. 结果表明,普通铸造方法得到的Fe－6.5%Si合金含有大量的B2和D0₃有序相,且有序度较高. 而快凝薄带晶粒细小,快的冷却速率有效地抑制了D0₃有序相的形成, 同时也降低了B2相的生长速度,使合金有序度较低, 从而使带材塑性得到明显改善.

Fe－6.5%Si alloy is one excellent soft magnetic material. However, due to the appearance of ordered phases, this alloy is very brittle at room temperature and is very hard to be fabricated into thin sheet by conventional rolling process. In this work, continuous Fe－6.5%Si ribbons of 20 mm in width, and 35－50 μm in thickness were fabricated by rapid quenching technique. The ribbons exhibited good ductility compared with ordinary cast ingots. TEM and XRD were employed to analyze the ordering and microstructure of the ordinary cast ingots and the ribbons. The long range order parameters of B2 ordered phase in these two alloys were calculated. The results showed that the cast ingot contained amounts of B2 and D0₃ ordered phases, and had high degree of order. While in rapid quenched ribbons, the grains were extremely fine, the formation of D0₃ ordering was suppressed effectively and the growth of B2 was largely decreased. The decreased ordering content and degree of order in rapid quenched ribbons lowered the anti－phase boundary energy, leading to the reduction in slip resistance, which improved the mobility of superlattice dislocations, and then obviously enhanced the ductility of the alloy.