Direction of a grain-boundary phase in submicrometre-grained iron

Producing bulk ultrafine-grained materials by severe plastic deformation

“…At that early stage, the main interest was devoted primarily to examining the unusual microstructures and properties of these materials rather than the precise signifi cance of the SPD processing. The fi rst paper in this area 5 received relatively little attention but a later report, 6 which provided clear evidence for UFG structure formation by SPD, became a classic publication and is currently listed with more than 300 separate citations. This early paper attempted also to identify similarities and differences between the grain boundaries in SPD-produced UFG materials and in the conventional nanocrystalline solids fabricated by consolidation procedures such as inert gas condensation.…”

Mössbauer spectroscopy of Fe-based nanomaterials

“…According to the results published in Refs. [1][2][3][4][6][7][8][9][10][11], for the MA(16 h) sample, we could expect lower P 0 and higher P 1 values than those shown in Table 2. P k values for the annealed sample are considerably different from those expected for the fully disordered state.…”

“…Thus, no second component [1][2][3][4][6][7][8][9][10][11] with the HFMF of H = 30.5-31.1 T and a wide distribution of HFMFs (Γ 1,6 = 0.4-1.6 mm/s) was found in the Mössbauer spectra of iron powders with a nanocrystalline structure. No second subspectrum with a HFMF of 21 T [7] was found in the Mössbauer spectrum of the milled iron powder subsequently annealed at 773 K ( Fig.…”

“…The estimates show that the volume fraction of the interface regions, provided the grain size is less than 10 nm, can be up to 50%. In a number of papers studying nanocrystalline α-Fe, it has been maintained that the interface regions essentially differ in the structure and fundamental magnetic properties (such as specific saturation magnetization, hyperfine interaction parameters, additional sextet in the α-Fe Mössbauer spectra, Curie temperature) from those in the bulk of the crystal [1][2][3][4][5][6][7][8][9][10]. On the other hand, it has been found [11][12][13][14][15][16] that irrespectively of the technique for producing nanocrystalline α-Fe (gas condensation, mechanical treatment in mills, high-pressure shearing), a possible significant contamination of α-Fe by impurities, contained in the medium, may occur.…”

Nanoscale States in Metals, Alloys, and Intermetallic Compounds: Methods of Manufacture, Structure, Properties

“…Формирование деформационными методами СМК структуры по-зволяет создавать удобные модельные объекты для эксперимен-тальных исследований межкристаллитных границ благодаря применимости к ним апробированных методов металлофизики и физики твердого тела [61,62].…”