Fe-6.5Si???D03?????????????????

用X射线直接比较法表征Fe-6.5%Si合金D03有序化,衍射强度受织构及三相多数衍射峰重叠影响而造成困难。选择D03{111}特征峰与三相重叠峰D03{444}、A2B2{222}比较,由于衍射面均为晶体学{111}晶面,结合有序化转变的特征可知该方法可避免织构的影响,两峰强度的比值实为D03相体积分数与表示其次近邻有序化程度参数的乘积。用方法表征了Fe-6.5%Si合金(温轧板A2相区退火后空冷)500℃时效过程中的D03有序化。结果表明,空冷首先使其转变为亚稳定的D03相,时效前期以B2相析出为主,后期两相分离及D03相有序化程度升高。分析认为该合金相的含量、有序化程度及分布形态均影响其磁性能。

D03 Ordering of Fe-6.5Si Alloy and Its Effect on Magnetic Properties

When direct comparison method by X-ray diffraction was used to characterize the D03 ordering reaction of Fe–6.5%Si alloy, diffraction intensity is affected by crystallography texture and overlapping of a great many diffraction peaks, which make it difficult to quantitatively analyze D03 ordering. {111} characteristic peak of D03 and overlapping peaks including {444} peak of D03 and {222} peak of A2 and B2 were selected to make comparison. Because the two diffraction planes are both {111} crystal plane on the basis of cubic structure, combined with analysis on characteristics of order transformation, the effect of texture can be avoided by this method. Ratio of the two peaks is the product of volume fraction of D03 and parameter indicating its ordering degree of the next nearest neighbor position. The D03 ordering reaction in the process of aging was characterized by this method, and the results show that metastable D03 ordering takes place after annealing and air cooling; B2 ordering and phase separation with increased degree of D03 ordering happened in the process of aging. It can be seen through analysis that, magnetic properties of Fe-6.5%Si alloy are affected by volume fraction of B2 and D03, ordering level and microstructure of two phases.