两种形状Nd-Fe-B粉末的混炼

Blend of Nd-Fe-B Magnetic Powders with Different Shape

摘要:

采用快淬法和雾化法制得的2种不同形貌的NdFeB磁粉，以尼龙12作粘结剂，研究了注射成形粘结磁体的混炼过程。结果表明：混合料的均匀度与混合时间的关系近似符合Boltzmann方程，磁通热损失率近似符合指数函数，混合料的流变符合假塑性流体的特征；平均粒度相当的粉末、雾化粉的临界充填率、初始均匀度和充分混合后的均匀度都高于快淬粉；相同剪切速率下，雾化粉的粘度远比快淬粉低。

Abstract:

NdFeB powders produced by melting spun and gas atomization are blended with nylon 12 binder and injected to make bonded magnet. Powder morphological analysis of the two kinds of powder is tested as well as powder size and size distribution. The rheological behaviors of both feedstock are pseudo-plastic fluid. Homogeneity of feedstock matches Boltzmann function and the irreversible loss of residual magnetism accords with exponent function. The critical powder loading rate, homogeneity and the rheological behavior of feedstock made by gas atomization are better than those of the melt spun.