Atom probe tomography (APT) is a tool for detailed chemical composition analysis of advanced structural material nanostructure. The use of different Atomic Probe Tomography (APT) devices requires a ...certification of these setups prior to conducting research. In this paper a method of comparing APT setups in order to evaluate the influence of the overall system configuration on the accuracy of obtained data is proposed. The collected data comparison is presented for the aluminum alloy Al–3.3Cu–2.5Mn–0.5Zr and structural steel 16Kh12МVSFBR gathered on the APPLE-3D (“PAZL-3D”) setup and on the new ATLAS (“ATLAZ”) unit, created through upgrading the ECOTAP. Comparison of the results confirms the feasibility of carrying out research of the same material on similar setups without significant distortion of the data under its analysis and interpretation.
Oxide dispersion strengthened steels possess better high-temperature creep and radiation resistance than conventionally produced ferritic/martensitic steels. This behaviour is mainly caused by the ...presence of highly dispersed and extremely stable oxide particles with diameters of a few nanometers. In this work the nanostructure of ODS Eurofer steel was investigated by means of tomographic atom probe and correlations with recent TEM and SANS studies were derived. The present investigation revealed nanoscaled clusters of typically 2
nm diameter containing not only yttrium and oxygen but also vanadium and nitrogen. Moreover, concentration of vanadium in particles was found to be higher than that of yttrium, which indicates the importance of these elements in cluster formation. The estimated average cluster number density is about 2
×
10
24
m
−3. These enriched zones might be evidently attributed to precursors of the larger precipitates observed by TEM. This conclusion is also supported by the similarities of the chemical composition inside enriched zones seen in both atomic probe and TEM data.
Our previous investigations of unirradiated ODS Eurofer by tomographic atom probe (TAP) revealed numerous nano-scaled features (nanoclusters) enriched in vanadium, yttrium and oxygen. In this work ...the effect of neutron irradiation on nanostructure behaviour of ODS Eurofer (9%-CrWVTa) was investigated. The irradiation was performed in the research reactor BOR-60 (Dimitrovgrad, Russia) where materials were irradiated at 330 °С to 32
dpa. TAP studies were performed on the needles prepared from parts of broken Charpy specimens. For all specimens except one, which was tested at 500
°C, the Charpy tests were performed at temperatures not exceeding the irradiation temperature. A high number density 2–4
×
10
24
m
−3 of ultra fine 1–3
nm diameter nanoclusters enriched in yttrium, oxygen, manganese and chromium was observed in the irradiated state. The composition of detected clusters differs from that for unirradiated ODS Eurofer. It was observed in this work that after neutron irradiation vanadium atoms had left the clusters, moving from the core into solid solution. The concentrations of yttrium and oxygen in the matrix, as it was detected, increase several times under irradiation. In the samples tested at 500
°C both the number density of clusters and the yttrium concentration in the matrix decrease by a factor of two.
The crystallization processes in Fe50Ni33B17 amorphous alloy have been investigated by transmission electron microscopy (TEM) and a three dimensional atom probe (3DAP). The γ-Fe,Ni FCC crystals, 25nm ...in size, were found in the amorphous alloy annealed at temperatures ranging 360–400°C for 1h. TEM demonstrates that the nanocrystals growth stops as the temperature rises. The formation of an amorphous layer enriched in boron at the border of γ-Fe,Ni nanocrystals responsible for the pinning of nanocrystals size was observed by 3DAP. The composition of an amorphous barrier by 3DAP was found to be Fe50Ni29B21. It was proposed that this composition reveals higher crystallization temperature, which is the reason of pinning nanocrystals growth.
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•The phenomenon of crystal growth pinning during annealing was found by TEM.•The formation of the barrier layer enriched in Boron was found by 3DAP.•The phenomenon can be described by “Crystallization-and-stop” model.
The effect of stabilizing crystal size in a melt-quenched amorphous Fe
50
Ni
33
B
17
ribbon is described upon crystallization in a temperature range of 360–400°С. The shape, size, volume fraction, ...and volume density have been investigated by transmission electron microscopy and X-ray diffraction methods. The formation of an amorphous layer of the Fe
50
Ni
29
B
21
compound was found by means of atomic-probe tomography at the boundary of the crystallite–amorphous phase. The stabilization of crystal sizes during annealing is due to the formation of a barrier amorphous layer that has a crystallization temperature that exceeds the crystallization temperature of the matrix amorphous alloy.
Atom probe tomography has been used to investigate nanoscale features in the yttrium oxide dispersion strengthened steel ODS Eurofer, which is a perspective structural material for the reactor cores. ...In the initial material, a large number (∼2 × 10
24
m
−3
) of ultrafine (∼2.5 nm in diameter) clusters enriched in yttrium, oxygen, nitrogen, and vanadium have been revealed. The investigation of the ODS Eurofer steel irradiated at 330°C to 32 dpa in the BOR-60 fast reactor has also revealed a large number of ultrafine (1–3 nm in diameter) nanoclusters significantly enriched in yttrium, oxygen, manganese, and chromium. In the irradiated material, an increase in the concentration of clusters and changes in the chemical composition of the clusters and matrix have been noted. The irradiation by fast neutrons leads to a partial transition of vanadium from the clusters into the surrounding matrix and to a general increase in the concentrations of yttrium and oxygen in the volumes under investigation.
It is shown that simulation experiments on the heavy-ion irradiation of structural materials used in nuclear power facilities can be used for tomographic atomic-stand studies. Experiments have been ...performed on irradiation of samples of advanced steel used in nuclear and fusion reactors EK-181 and ODS Eurofer by iron ions to damaging dose 10 dpa. The steel is characterized by the presence of a large number of nanosize (2–3 nm) clusters, dispersion-hardening these materials. Irradiation was performed on the TIPr-1 heavyion linear accelerator. Atomic-probe studies of irradiated samples reveal a change in the composition of nanosize clusters under irradiation.
The effect of stabilizing crystal size in a melt-quenched amorphous Fe.sub.50Ni.sub.33B.sub.17 ribbon is described upon crystallization in a temperature range of 360-400degreesC. The shape, size, ...volume fraction, and volume density have been investigated by transmission electron microscopy and X-ray diffraction methods. The formation of an amorphous layer of the Fe.sub.50Ni.sub.29B.sub.21 compound was found by means of atomic-probe tomography at the boundary of the crystallite--amorphous phase. The stabilization of crystal sizes during annealing is due to the formation of a barrier amorphous layer that has a crystallization temperature that exceeds the crystallization temperature of the matrix amorphous alloy. Keywords: amorphous ribbon, crystallization, nanocrystals, transmission electron microscopy (TEM), atomic-probe tomography
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•High domain wall mobility of Fe-Ni-based microwires.•Enhancement of domain wall velocity and mobility in Fe-rich microwires after annealing.•Observation of areas enriched by Si and ...depleted by B after annealing.•Phase separation in annealed Fe-Ni based microwires in metallic nucleus and near the interface layer.
We studied the magnetic properties and domain wall (DW) dynamics of Fe47.4Ni26.6Si11B13C2 and Fe77.5Si7.5B15 microwires. Both samples present rectangular hysteresis loop and fast magnetization switching. Considerable enhancement of DW velocity is observed in Fe77.5Si7.5B15, while DW velocity of samples Fe47.4Ni26.6Si11B13C2 is less affected by annealing. The other difference is the magnetic field range of the linear region on dependence of domain wall velocity upon magnetic field: in Fe47.4Ni26.6Si11B13C2 sample is considerably shorter and drastically decreases after annealing. We discussed the influence of annealing on DW dynamics considering different magnetoelastic anisotropy of studied microwires and defects within the amorphous state in Fe47.4Ni26.6Si11B13C2. Consequently we studied the structure of Fe47.4Ni26.6Si11B13C2 sample using X-ray diffraction and the atom probe tomography. The results obtained using the atom probe tomography supports the formation of the B-depleted and Si-enriched precipitates in the metallic nucleus of Fe-Ni based microwires.
The results of an analysis of data from the SERP-Е-184 experiment devoted to studying mechanisms of the production of charmed particles in proton–nucleus interactions at 70 GeV and their decays are ...presented. The data in question were obtained upon irradiating the SVD-2 active target consisting of carbon, silicon, and lead plates with a beam of 70-GeV protons. A detailed simulation on the basis of the FRITIOF7.02 and GEANT3.21 code packages made it possible to optimize event-selection criteria and to calculate the detection efficiency for Λ
c
+
baryons. After selecting a signal from the threebody decay of a Λ
c
+
baryon, the inclusive cross section for its production at near-threshold energies, its lifetime, and the parameter of the
A
dependence of the cross section were found. The Λ
c
+
-baryon yields are tabulated along with data from other experiments and theoretical predictions.
