Rahim Sabbaghizadeh

Dependence of microstructure and magnetic properties of (Nd,Pr)-(Fe,Ti,C)-B melt-spun ribbon on quenching wheel speed

Melt-spun ribbons with nominal composition of Nd6Pr1Fe76B12Ti4C1 have been prepared at different quenching wheel speeds (5, 7.5, 10 and 15 m/s) and investigated for microstructural and magnetic properties. The asspun ribbons were examined by using x-ray diffractometry (XRD) with Cu-kα radiation and differential scanning calorimetry (DSC) and vibrating sample magnetometry (VSM). Based on the results obtained, it was shown that the lower speeds increased the magnetic properties. Hence, a uniform Nd2Fe14B/Fe3B nanocomposite structure with fine soft grains can be developed at an optimum quenching wheel speed of about 5 m/s. Further, it is seen that the higher quenching wheel speed leads to a lower grain size and higher amorphous phase amount.

Effects of heat treatment on the magnetic properties of melt-spun Nd6Pr1Fe76B12Ti4C1Co3 nanocomposite ribbons

In this study, the effects of different annealing temperatures on the structure and magnetic properties of Nd-Fe-B nanocomposite permanent magnetic alloys with nominal composition of Nd6Pr1Fe76B12Ti4C1Co3 have been investigated. Melt Spinning (one of the most predominant ribbon synthesize methods) with constant wheel speed of V = 25 m/s was employed to produce ribbons. As-spun ribbons were examined by using xray diffractometer (XRD) with Cu-Kα radiation and differential scanning calorimetry (DSC). The ribbons were annealed at different temperatures in order to extract the best magnetic properties. The XRD and electron microscopy technique results confirm that grains are in the size of less than 50 nm. In addition, optimum magnetic properties were obtained at 720°C annealed temperature.

Influence of Annealing Temperature on the Magnetic Properties of Rapidly Quenched (Nd,Pr)2-(Fe,Co,Ga,Ti,C)14B/α-Fe Nanocomposite Ribbons

The effects of different heat treatment temperatures on the structure and magnetic properties of Nd-Fe-B nanocomposite permanent magnetic alloys with nominal composition of Nd9.4Pr0.6Fe74.5Co6B6Ga0.5Ti1.5C1.5 have been investigated. The most practical method to produce nanostructured metallic materials is rapid solidification. Melt spinning with constant wheel speed of  m/s was employed to produce ribbons. As-spun ribbons were examined by using differential scanning calorimetry (DSC) and X-ray diffractometer (XRD) with Cu-kα radiation. The ribbons were annealed at different temperatures in order to extract the best magnetic properties. The XRD and electron microscopy technique results confirm that grains are in the size of less than 50 nm. In addition, optimum magnetic properties were obtained at 700°C annealed temperature.