Influence of Alloying Elements Zr, Nb and Mo on the Microstructure and Magnetic Properties of Sintered Pr-Fe-Co-B Based Permanent Magnets

Abstract:

The addition of alloying elements on rare-earth permanent magnets is one of the methods used to improve the magnetic properties. This present work evaluates the influence of alloying elements such as Zr, Nb and Mo on the microstructure and magnetic properties of sintered Pr-FeCo-B based permanent magnets. The permanent magnets were produced by the conventional powder metallurgy route using powder obtained by hydrogen-decrepitation (HD) method from as cast alloys. In order to produce the magnet Pr₁₆Fe_66,9Co_10,7B_5,7Cu_0,7 without alloying elements the mixture of alloys method was employed, mixing two compositions: Pr₂₀Fe₇₃B₅Cu₂ (33% w.t) and Pr₁₄Fe₆₄Co₁₆B₆ (67% w.t). With the purpose of evaluating the influence of the alloying elements, the Pr₁₄Fe₆₄Co₁₆B₆X_0,1 (where X= Zr, Nb or Mo) (67% w.t) alloy was employed. The characterization of the alloys and the magnets was carried out using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS) and the magnetic properties were measured using a permeameter. The magnet without any additions presented the highest intrinsic coercivity (μ_0iH_c = 748 KA.m-1) while the magnet with Nb addition presented higher remanence (Br = 1,04 T). The magnet with Zr addition presented the highest maximum energy product (BH_máx = 144 KJ.m^-3), and the magnet with Mo addition showed the highest squareness factor (SF = 0,73).

• Periodical: Materials Science Forum (Volume 930)
• Pages: 440-444
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.930.440
• Online since: September 2018
• Authors: Melissa Rohrig Martins da Silva*, R.G.T. Fim, S.C. Silva, Julio César Serafim Casini, P.A.P. Wendhausen, H. Takiishi
• Keywords: Hydrogen Decrepitation, Pr-Fe-Co-B Based Magnets, Rare-Earth Permanent Magnets

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