Influence of W Addition on Phase Constitution, Microstructure and Magnetic Properties of the Nanocrystalline Pr₉Fe₆₅W_xB_26-x (Where: x = 2, 4, 6, 8) Alloy Ribbons

• Main Authors: Katarzyna Filipecka, Piotr Pawlik, Andrzej Kozdraś, Waldemar Kaszuwara, Jarosław Ferenc, Jacek Filipecki
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Materials
• Subjects: rare earth; permanent magnets; rapid solidification; magnetic properties; X-ray diffraction; Mössbauer spectroscopy
• Online Access: https://www.mdpi.com/1996-1944/13/10/2229

The aim of the present work was to investigate an influence of W addition on the phase constitution, microstructure and magnetic properties of the Pr₉Fe₆₅W_xB_26-x (where: x = 2, 4, 6, 8) alloy ribbons. Ribbons were obtained using the melt-spinning technique under low pressure of Ar. The as-cast samples were fully amorphous and revealed soft magnetic properties. These facts were confirmed by X-ray diffractometry, Mössbauer spectroscopy and magnetic measurements. Differential scanning calorimetry and differential thermal analysis allowed us to determine the thermal stability parameters of the amorphous phase. The Kissinger plots were constructed in order to calculate the activation energies for crystallization. Heat treatment carried out at various temperatures caused changes in the phase constitution and magnetic properties of the alloys. The phase analysis has shown the presence of the hard magnetic Pr₂Fe₁₄B and paramagnetic Pr_1+xFe₄B₄ phases. Additionally, for the x = 2 and x = 6 alloys, a crystallization of soft magnetic Fe₂B and α-Fe phases was observed. The Mössbauer spectroscopy allowed us to determine the volume fractions of constituent phases formed during annealing. The microstructure of annealed ribbons was observed using transmission electron microscopy.