Hamburg 2001 – scientific programme

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AM: Magnetismus

AM 8: Dauermagnetische Werkstoffe und Legierungen

AM 8.3: Talk

Tuesday, March 27, 2001, 12:00–12:15, S 5.4

Highly coercive (Pr,Nd)FeB-type magnets produced by intensive milling and melt-spinning — •A. Bollero¹, O. Gutfleisch¹, K.-H. Müller¹, L. Schultz¹, G. Drazic², and S. Kobe² — ¹IFW Dresden, Institut für Metallische Werkstoffe. POB 270016, Dresden — ²Jozef Stefan Institute, Jomaova, 1001 Ljublana, Slovenia

Highly coercive isotropic (Pr_1−xNd_x)₂Fe₁₄B-type magnets (0 ≤ x ≤1) have been prepared using high energy ball milling and melt-spinning techniques. Samples containing Dy (1at.%) and Zr (0.1at.%) exhibited an improved stability against grain growth on annealing. Differential scanning calorimetry studies revealed significant differences in the thermal

behavior of the alloys produced by both techniques. High coercivities of µ₀H_c = 2.7T and 2.5T and remanences of J_r = 0.64T and 0.72T were found after annealing Pr₁₅DyFe_75.9B₈Zr_0.1 ribbons and as-milled powders, respectively. Transmission electron microscopy showed an improved microstructure for the alloys containing Dy and Zr, which results in a wider processing window for the production of highly coercive nano-crystalline materials.