558
O. I. Kushnerov et al.
and manufacturing of MGs. The HE-MGs (as happens with substances that simultaneously belong to different types of materials [7, 8]) have excellent physical and
mechanical properties combining the advantages of both metallic glasses and HEAs.
So, HE-MGs exhibit considerable potential for various technical applications [9]. In
particular, MGs usually are excellent soft magnetic materials. They have high saturation magnetization, low coercivity, and power loss. Till now, serials of HE-MG
systems have been synthesized [1, 9–13].
This study is dedicated to developing a new nanostructured
Fe 25 B 17.5 Co 21.35 Nb 3.65 Ni 25 Si 7.5 HE-MG which combines good thermal stability
with high mechanical and soft magnetic properties.
2 Materials and Methods
The as-cast sample of Fe–B–Co–Nb–Ni–Si alloy with a nominal composition
of Fe 25 B 17.5 Co 21.35 Nb 3.65 Ni 25 Si 7.5 (in at.%) was prepared with a Tamman hightemperature electric furnace in the argon gas flow using a copper mold. The mass
losses during ingot preparation did not exceed 1% and the average rate of cooling
was ~10
2 K/s. The as-cast ingot was thereafter remelted and the nanostructured films
were obtained from the melt by splat quenching (SQ) technique. A technique for
splat quenching used in the present work consisted of rapid cooling of melt drops
upon their collision with the internal surface of a rapidly rotating hollow cylinder of
copper. The cooling rate was estimated following the methodology proposed in [3].
We used the expression (1)
V =
αϑ
cρδ
,
(1)
where c is the heat capacity of film, ρ is the film density, α is the coefficient of heat
transfer, ϑ is the excess temperature of the film, and δ is the thickness of film [3].
Considering the thickness of fabricated splat quenched films, the estimated rate of
cooling was ~10
6 K/s. The X-ray diffraction analysis (XRD) was carried out using a
DRON-2.0 diffractometer with monochromatized Cu Kα radiation. The diffraction
patterns were processed using QualX2 software [14]. The temperature dependencies of electrical resistivity of the film were measured by the four-point technique
upon continuously heating and subsequently cooling in the high vacuum with a
pressure of 4 · 10
−2 Pa. The heating rate from room temperature to ~1010 K was
0.2 K/s. Annealed films were used for structural studies by X-ray diffraction analysis (with a photographic registration, in a Debye camera on the URS-2.0 diffractometer in filtered Co K α radiation). Debyegrams were digitally microphotometred and processed using a qualitative phase analysis software Qualx2. The thermal
behavior of the nanostructured films was studied by a differential thermal analysis
technique (DTA) at a heating rate of 0.2 K/s. The microhardness was examined
O. I. Kushnerov et al.
and manufacturing of MGs. The HE-MGs (as happens with substances that simultaneously belong to different types of materials [7, 8]) have excellent physical and
mechanical properties combining the advantages of both metallic glasses and HEAs.
So, HE-MGs exhibit considerable potential for various technical applications [9]. In
particular, MGs usually are excellent soft magnetic materials. They have high saturation magnetization, low coercivity, and power loss. Till now, serials of HE-MG
systems have been synthesized [1, 9–13].
This study is dedicated to developing a new nanostructured
Fe 25 B 17.5 Co 21.35 Nb 3.65 Ni 25 Si 7.5 HE-MG which combines good thermal stability
with high mechanical and soft magnetic properties.
2 Materials and Methods
The as-cast sample of Fe–B–Co–Nb–Ni–Si alloy with a nominal composition
of Fe 25 B 17.5 Co 21.35 Nb 3.65 Ni 25 Si 7.5 (in at.%) was prepared with a Tamman hightemperature electric furnace in the argon gas flow using a copper mold. The mass
losses during ingot preparation did not exceed 1% and the average rate of cooling
was ~10
2 K/s. The as-cast ingot was thereafter remelted and the nanostructured films
were obtained from the melt by splat quenching (SQ) technique. A technique for
splat quenching used in the present work consisted of rapid cooling of melt drops
upon their collision with the internal surface of a rapidly rotating hollow cylinder of
copper. The cooling rate was estimated following the methodology proposed in [3].
We used the expression (1)
V =
αϑ
cρδ
,
(1)
where c is the heat capacity of film, ρ is the film density, α is the coefficient of heat
transfer, ϑ is the excess temperature of the film, and δ is the thickness of film [3].
Considering the thickness of fabricated splat quenched films, the estimated rate of
cooling was ~10
6 K/s. The X-ray diffraction analysis (XRD) was carried out using a
DRON-2.0 diffractometer with monochromatized Cu Kα radiation. The diffraction
patterns were processed using QualX2 software [14]. The temperature dependencies of electrical resistivity of the film were measured by the four-point technique
upon continuously heating and subsequently cooling in the high vacuum with a
pressure of 4 · 10
−2 Pa. The heating rate from room temperature to ~1010 K was
0.2 K/s. Annealed films were used for structural studies by X-ray diffraction analysis (with a photographic registration, in a Debye camera on the URS-2.0 diffractometer in filtered Co K α radiation). Debyegrams were digitally microphotometred and processed using a qualitative phase analysis software Qualx2. The thermal
behavior of the nanostructured films was studied by a differential thermal analysis
technique (DTA) at a heating rate of 0.2 K/s. The microhardness was examined