The results of studying the possibility of fabricating the Pr₂Fe₁₄B/α-Fe composite materials by oxidation of the Pr–Fe–B alloy in a fluidized-bed jet mill are presented. It is shown that the use of the standard powder metallurgy technology supplemented by oxidation of the Pr–Fe–B alloy in a fluidized-bed jet mill for rare-earth magnetically hard materials (MHMs) makes it possible to fabricate Pr₂Fe₁₄B/α-Fe composites with high magnetic characteristics. It is established that, when fabricating finely dispersed powders according to the proposed technology in the argon medium containing 0.2 vol % oxygen, residual magnetic induction (B_r) occurs with an insignificant drop in the coercive force (jH_c). This effect causes a 5% increase in the maximal energy product (BH)_max. The almost complete oxidation of the highly praseodymium phase Pr_xFe occurs with a further increase in the oxygen concentration, which leads to an abrupt drop in the coercive force and, consequently, a decrease in (BH)_max. The particles of the α-Fe phase formed due to the oxidation of the magnetic material are formed at the boundaries between the grains of the Pr₂Fe₁₄B phase. Herewith, the highest magnetic characteristics are implemented if the α-Fe particles are separated from the grains of the main magnetic phase by thin interlayers of nonmagnetic phases, which makes it possible to hold a high level of jH_c for sintered MHM samples. Herewith, the optimal thickness of the α-Fe layers is 0.2–0.3 μm. The α-Fe layers formed with an oxygen content of 0.3 vol % turned out considerably thicker (from 0.8 to 1.1 μm), which leads to an almost 10% decrease in the coercive force of the samples and 3–7% decrease in other magnetic parameters (B_r, (BH)_max). Thus, when controlling the oxygen content in the working medium of the jet mill, we can vary the thickness of the interlayer of the forming α-Fe phase in the Pr₂Fe₁₄B/α-Fe composite material and control its magnetic parameters.

中文翻译：

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研究在流化床气流磨中通过Pr-Fe-B合金氧化制备Pr 2 Fe 14 B /α-Fe复合材料的可能性

提出了研究在流化床气流磨中通过Pr-Fe-B合金氧化制备Pr ₂ Fe ₁₄ B /α-Fe复合材料的可能性的结果。结果表明，在稀土磁性硬质材料（MHM）的流化床喷射磨机中，使用标准粉末冶金技术并辅以Pr-Fe-B合金的氧化，可以制造Pr ₂ Fe ₁₄ B /α-Fe复合材料具有高磁性。已经确定，当根据所提出的技术在含氧量为0.2％（体积）的氩气介质中制备细分散的粉末时，会产生残留的磁感应强度（B _r），而矫顽力（B）的下降却很小。jH _c）。此效果导致最大能量乘积（BH）_max增加5％。高相Pr _x Fe的几乎完全氧化随着氧浓度的进一步升高而发生，这导致矫顽力突然下降，因此（BH）_max减小。由于磁性材料的氧化而形成的α-Fe相的颗粒形成在Pr ₂ Fe ₁₄的晶粒之间的边界处。B相。因此，如果通过非磁性相的薄夹层使α-Fe颗粒与主磁性相的晶粒分离，则可以实现最高的磁性，这对于烧结的MHM样品可以保持高水平的jH _c。因此，α-Fe层的最佳厚度为0.2-0.3μm。氧含量为0.3％（体积）的α-Fe层厚得多（从0.8到1.1μm），这导致样品的矫顽力降低了近10％，其他磁性降低了3-7％。参数（B _r，（BH）_max）。因此，当控制喷射磨的工作介质中的氧含量时，我们可以改变Pr ₂ Fe ₁₄ B /α-Fe复合材料中形成的α-Fe相的中间层的厚度，并控制其磁参数。