Peculiarities of the HDDR Processes at Low Hydrogen Pressures in Nd—Fe—B System Alloys
I. I. Bulyk1, А. M. Trostianchyn1, V. V. Burkhovetskyi2, V. Yu. Tarenkov2
1Karpenko Physico-Mechanical Institute, NAS of Ukraine, 5, Naukova Str., 79060 Lviv, Ukraine
2Donetsk Institute for Physics and Engineering Named after O.O. Galkin, NAS of Ukraine, 72 R. Luxembourg Str., 83114 Donetsk, Ukraine
Received: 22.04.2013; final version - 05.06.2014. Download: PDF
The features of hydrogenation, disproportionation, desorption, recombination (HDDR) processes in Nd11.8Fe82.3B5.9 and Nd16Fe76B8 alloys under hydrogen pressure of 0.05 MPa in the temperature range of 20—840°C are studied by means of differential thermal analysis (DTA), X-ray diffraction analysis and scanning electron microscopy (SEM) methods. Superfine Nd2Fe14B phase with up 200 nm thickness lamellar microstructure is formed in some alloys’ areas after solid HDDR under low hydrogen pressure. The principal possibility of fine-grained magnetic-anisotropy microstructure formation in Nd—Fe—B system alloys is shown in the cases of presence of small amount of initial ferromagnetic Nd2Fe14B phase among disproportionated products.
Key words: hydrogen initiated phase transformations, magnetic anisotropy, ferromagnetic alloys, Nd2Fe14B, hydrogen technology.
URL: http://mfint.imp.kiev.ua/en/abstract/v36/i07/0903.html
DOI: https://doi.org/10.15407/mfint.36.07.0903
PACS: 61.72.Ff, 75.30.Gw, 75.50.Tt, 75.50.Ww, 75.75.Cd, 81.07.Wx, 81.40.Rs
Citation: I. I. Bulyk, А. M. Trostianchyn, V. V. Burkhovetskyi, and V. Yu. Tarenkov, Peculiarities of the HDDR Processes at Low Hydrogen Pressures in Nd—Fe—B System Alloys, Metallofiz. Noveishie Tekhnol., 36, No. 7: 903—916 (2014) (in Ukrainian)