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Ключевые слова: сплавы неодим-железо-бор, сплавы самарий-кобальт, метод
ГДДР, водородная обработка, наноструктура, магнитная анизотропия, спекание,
пористость, фазовые превращения, диффузия, рентгеновкий фазовый анализ,
коэрцитивная сила.

SUMMARY

Borukh I. V. Influence of hydrogen treatment on structure and magnetic
properties of materials based on Nd Fe B and SmCo intermetallics. Manuscript.
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Thesis for a degree of Candidate of Sciences ( Engineering) in speciality 05.02.01 –
materialsscience. H. V. Karpenko Physico-Mechanical Institute NASU, Lviv, 2021.
The thesis for a degree of Candidate of Sciences (Engineering) is devoted to the
development of the method of obtaining sintered nanostructured magnets from rare earth –
transition metal alloys using hydrogen – initiated phase transformations – the HDDR
method. The conditions of processing the Nd 11,7 Fe 82,3 B , Nd Fe B ; Nd 11,7 Fe 81,1 Zr B ,
1,2
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Nd Fe 73,9 Zr B and Sm(Co,T) , T=Zr, V, Ti ferromagnetic materials at separate stages of
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production of sintered magnets: grinding, pressing and sintering, are investigated. The
relationship between the parameters of grinding alloys and the parameters of hydrogen
treatment to obtain magnetically anisotropic materials with crushed to the nanolevel
microstructure is studied. A method for sintering the studied ferromagnetic alloys at low
temperatures in hydrogen to obtain nanostructured materials with low porosity is
developed. It is found that to obtain sintered nanostructured magnets, materials based on
Nd Fe B must be treated in hydrogen under pressure up to 0.05 MPa at a temperature of
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700°C, in vacuum- at a temperature of 850°C. Materials based on SmCo must be treated
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in hydrogen under a pressure of 0.1-0.5 MPa at a temperature of 650°C, in vacuum – at a
temperature of 950°C. The prospects of heat treatment of sintered magnets in hydrogen to
increase their magnetic properties with the achievement of the coercive force of SmCo
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magnets of about 50 kE are shown.
For the first time, a high coercivity of 49.7 kOe is obtained in the HDDR treatment of
SmCo and for the first time the sintering temperature is reduced to 950°C during sintering
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of pressed elements from powders of SmCo , Sm(Co,Zr) , Nd 11,7 Fe 81,1 Zr B ,
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1,2
Nd Fe 73,9 Zr 1B alloys.
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The conditions for processing the Nd-Fe-B-Zr alloys in hydrogen under which there
are the remains of the Nd Fe B ferromagnetic phase and after which, due to processing by
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HDDR, the Nd-Fe-B-Zr alloys are nanostructured and magnetically anisotropic, are
established.
The grinding conditions of Sm-Co-Zr alloys after which the grinded powders are
magnetically anisotropic are studied.
Practical recommendations proposed in the research are protected by two patents of
Ukraine.
Keywords: neodymium-iron-boron alloys; samarium-cobalt alloys; HDDR method;
hydrogen treatment; nanostructure; magnetic anisotropy; texture; sintering; porosity; phase
transformations; diffusion; X-ray phase analysis; coercivity.