Showing 2 results for Melt Spinning
Kaviani S., Marashi S. P. H.,
Volume 1, Issue 3 (9-2004)
Abstract
The surface condition and microstructure of near stoichiometric (Fe823Ndll.8B5.9) Nd-Fe-B alloy ribbons and the effect of melt spinning parameters were investigated using optical, scanning and transmission electron microscopes (SEM, TEM). The formation of gas pockets on the roll surface of the ribbons during melt spinning can prevent heat transform and result in local coarse grains. The local thickness would also be less in these places and thus perforates preferentially during ion beam milling. Therefore different areas of the sample should be carefully observed in the TEM. Reducing inert gas pressure in the chamber will eliminate the gas pockets. As a general trend, decrease in the ribbon thickness and mean Nd2 Fe14B grain size were observed on increasing the roll speed. By careful adjustment of the melt spinning parameters, the nanostructure will develop. An orientation relationship was found between Nd2 Fe14B and α-Fe precipitates for coarse grain samples melt spun at low roll speed. Dark field image of such grain also shows that some of these α-Fe precipitates have the same orientation. X-ray diffraction evident the development of texture by decreasing the roll speed.
S. Mirzaei, H. Saghafian, A. Beitollahi, J. Świerczek, P. Tiberto,
Volume 16, Issue 3 (9-2019)
Abstract
In the present research, rapidly solidified Fe85.3B11P3Cu0.7 ribbons were prepared by melt spinning process. The microstructural variation as well as magnetic properties of the as-spun and annealed ribbons were characterized by X-ray diffraction (XRD), transmission Mossbauer spectroscopy and alternating gradient field magnetometer (AGFM). The results show two separated distinct exothermic peaks during heating resulting from the phase transition from amorphous to α-Fe and then to Fe3B, respectively. The study of magnetic properties in the amorphous and nanocrystalline states revealed that annealing the amorphous ribbons at 440˚C for 10 minutes gives rise to a significant increase in saturation magnetization (220 emu/g) which makes this alloy a good candidate for power applications.
