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In this paper, some luminosity, focusing and resolution properties of a double-crystal (n,-m) dispersive setting which contains a bent perfect Si(111) crystal as a first one and a sandwich consisting of four different bent perfect crystals (BPC) Si(220), Si(400), Ge(111) and Ge(311) located at the second axis, is introduced with the aim of possible use in high-resolution diffractometry. The properties were investigated at a neutron wavelength of 0.162 nm. It was shown that a narrow and highly collimated and high-resolution monochromatic beam can be obtained. By using a standard polycrystalline pin of α-Fe, the resolution of the three-axis diffraction performance, namely, in the vicinity of the scattering angle 2 θ S = 90 ∘ was tested in detail. It has been found that the dispersive double-crystal (DC) setting represents a high-resolution monochromator alternative, e.g. in powder diffraction which could be used at high-flux neutron sources.

Focusing 3-axis diffractometer set-up equipped with bent perfect crystal (BPC) monochromator and analyzer offers the sensitivity in determination of strains Dd/d < 10-4 in polycrystalline materials which is about one order of magnitude higher with respect to that of conventional 2-axis neutron scanners. It also offers possibility of line profile analysis for reasonable sample volumes and counting times. In this paper, the feasibility of using the 3-axis set-up even for measurements of rather large bulk polycrystalline samples with an acceptable resolution is presented. As the 3-axis set-up exploits focusing in real and momentum space, by a proper adjustment of the curvature of the analyzer, a high-resolution determination of the lattice changes can also be achieved even on large irradiated gauge volumes, though with a slightly relaxed resolution. It can be successfully exploited namely, in the strain/stress measurements on samples exposed to an external load, e.g. in tension/compression rig, in aging machine etc. In addition to the original performance where the analysis is carried out by rocking the BPC analyzer and the neutron signal registered by a point detector, a new alternative is offered which uses a fixed rocking angle position of the analyzer and the detector signal is registered by a one-dimensional position sensitive detector (PSD). This trick makes possible in some cases the elastic strain/stress measurements considerably faster and thus reduces the drawback of the time consuming step-by-step analysis.

Structural analysis in the range of characteristic sizes from 1 nm to ~1.5 µm was performed for SiO2–TiO2 aerogels prepared in supercritical CO2, isopropanol, hexafluoroisopropanol, or methyl-tert-butyl ether using small-angle X-ray scattering and neutron scattering complementary methods. A two-level model that accounts for scattering by individual inhomogeneities and their aggregates, which have fractal properties, satisfactorily describes the aerogel structures over the entire range of scales. It is shown for the first time that the titania concentration is the key factor in the small-angle neutron and X-ray scattering by SiO2–TiO2 aerogels. The phase composition of an aerogel does not significantly affect the aerogel structure in the range of scales from 1 nm to ~1.5 µm, as probed by small-angle X-ray and neutron scattering.

This paper summarizes recent results of an exhaustive experimental study of multiple Bragg reflections accompanying allowed as well as forbidden reflections. The multiple reflection observations were carried out in the frame of Bragg diffraction optics experiments on cylindrically bent perfect single crystals. It has been found that depending on the thickness and curvature of the crystal slabs and the diffraction geometry (reflection, transmission), many strong multiple reflections can be excited which can also be used as a source of highly monochromatic and highly collimated beams for further experiments requiring extremely high resolution.

Strong multiple Bragg reflections (MBRs) which can be realized in a bent-perfect-crystal (BPC) slab provide a monochromatic beam of excellent resolution parameters. For identifying MBR effects in the BPC Si crystal, we used the method of azimuthal rotation of the crystal lattice around the scattering vector of the primary forbidden Si(200) reflection for a fixed chosen wavelength. In this paper, several azimuthal scans searching strong MBR effects with the intention of a possible practical exploitation for very high-resolution diffractometry are presented.

The evolution of the Ti–Zr alloy microstructure (residual stresses, as well as microstress) during annealing after severe plastic deformation is reported. A strong residual macro-stresses relief starts at temperature of 530–540°C. A steep decrease continues up to 580°C and a further slight decrease up to 600°C. Microstrain (caused by the high dislocation density created by equal channel angular pressing) is almost constant up to 300°C, and then begins to decrease gradually due to recovery. The microstrain decrease accelerates at 560°C and is finished at 580°C. Most probably, this is caused by recrystallization. The information obtained is important for possible microstructure modifications and tuning via post-process heat treatment.

An alternative neutron diffractometer performance, which documents the feasibility of using a high-resolution three-axis neutron diffractometer for elastic and plastic deformation studies of bulk metallic polycrystalline samples, is presented. Contrary to the conventional double-axis setting, the suggested alternative consists of an unconventional three-axis set-up employing a bent perfect crystal monochromator and an analyzer with a polycrystalline sample in between. Though the alternative is, for measurements, much more time-consuming, its sensitivity to the change of the diffraction angle of the sample is, however, substantially higher and permits also plastic deformation studies on the basis of analysis of the diffraction line profiles. Moreover, much larger widths (up to 10 mm) of the irradiated gauge volumes can be investigated when just slightly affecting the angular resolution properties of the experimental setting.

The structure of detonation nanodiamond aqueous dispersions grafted by europium or gadolinium atoms was investigated by small-angle neutron scattering over a wide size scale from 1 to 3000 nm. Simi...

The effect of the ultrafine grained silicon nitride and yttria addition to the morphological, structural, mechanical and magnetic properties of the ceramic dispersion strengthened 316 L stainless steels prepared by powder technology has been studied. Four composites have been prepared: 316 L/0.33 wt.% Si3N4, 316 L/1 wt.% Si3N4 (CDS) and 316 L/0.33 wt.% Y2O3, 316 L/1 wt.% Y2O3 (ODS). Spark plasma sintering (SPS) was used for fast compaction of milled composite powders. The hardness values have been found to be significantly higher in the cases of CDS and ODS samples in comparison to reference sample, whereas the ODS composites had lower smaller hardness than the CDS composites regardless the content of additives. The magnetic characterization of samples demonstrated that the samples exhibit ferromagnetic property already before ageing and a larger ferromagnetic component was observed as a result of thermal aging. It was proven that in the case of ODS and CDS samples with a low amount of Y2O3 or Si3N4 the saturation magnetization was slightly dependent on ageing time, however, it exhibited a noticeable change with ageing both at 600 and 800 °C for samples containing higher amount of additives.

This paper reports the results of the comparative structural characterization of detonation nanodiamond particles and their aggregates in hydrosols and hydrogels by small-angle scattering (SAS) techniques. The data from different neutron and X-ray (synchrotron radiation) diffractometers cover a wide range of momentum transfer and show multilevel structure organizations at the size scale from 1 to 1000 nm and higher. For this purpose, in addition to the conventional SAS techniques the methods of very small-angle and ultrasmall-angle neutron scattering were applied. The fraction of nanodiamond particles in the aggregates is determined. A complex two-step mechanism of nanodiamond cluster association into a network during the sol–gel transition is revealed. It is assumed that a reason for the reversibility of this process is a different compactness of the corresponding structural levels defined by different fractal organizations.

Understanding the tempering behavior of medium carbon steels is mandatory if their mechanical properties are to be improved. For an optimal technology to be developed for this purpose, a substantial experimental basis is needed to extract quantitative information on the microstructure of the tempered material. This paper reports on the characterization of microstructural changes induced by tempering in medium-carbon steels alloyed with Si, Cr, Cu, and Mn using state-of-the-art experimental techniques. Complementarities among these techniques are highlighted. The evolution of transition carbides, cementite, and copper precipitates is described using data from X-ray diffraction, small and ultra-small angle neutron diffraction, transmission electron microscopy, and dilatometry observation. The effects of silicon, chromium, and copper on the mechanism of carbide and copper precipitation are discussed. The considerable changes found in the size and volume of copper precipitates correlate well with the difference in the yield stress between tempered steels with and without copper.

Resolution properties of the unconventional high-resolution neutron diffraction three-axis setup for strain/stress measurements of large bulk polycrystalline samples are presented. Contrary to the conventional two-axis setups, in this case, the strain measurement on a sample situated on the second axis is carried out by rocking the bent perfect crystal (BPC) analyzer situated on the third axis of the diffractometer. Thus, the so-called rocking curve provides the sample diffraction profile. The neutron signal coming from the analyzer is registered by a point detector. This new setup provides a considerably higher resolution (at least by a factor of 5), which however, requires a much longer measurement time. The high-resolution neutron diffraction setting can be effectively used, namely, for bulk gauge volumes up to several cubic centimeters, and for plastic deformation studies on the basis of the analysis of diffraction line profiles, thus providing average values of microstructure characteristics over the irradiated gauge volume.

In this paper the results of particular studies of multiple Bragg reflection (MBR) effects accompanying a strong Si(111) reflection in the cylindrically bent perfect crystal at the neutron wavelength of 0.162 nm are presented. Contrary to a common view that MBR effects could be considered negligible or represent maximally a few percent of an effect related to a single allowed reflection, it is shown that in the case of a homogeneously deformed perfect single crystal (in this case cylindrically bent Si crystal) and particular diffraction geometry they can be even several times higher.

Barium titanate coatings were first time sprayed by a high feed-rate plasma torch with water stabilization. Two power levels of the torch were applied. Two substrate materials were used—stainless steel and carbon steel. Various substrate preheating levels from 125 to 450 °C were applied to change the cooling conditions. Microstructure, phase composition including crystallinity quantification, surface roughness and microhardness were evaluated. Dielectric measurements proved that coatings with medium-level relative permittivity and with stable loss factor course versus frequency of the AC electric field were fabricated by spraying. The cold substrates provided coatings with low reflectivity and visibly darker surface compare to the hot substrates. The coatings exhibited good dielectric properties—on the top of an expectable range for plasma-sprayed BaTiO3. This study is targeted to coatings prospective for electrical industry, namely via optimization of conditions at the high feed-rate spraying.

The internal structure of empty porous micro- and macroporous magnetic glasses and the related nanocomposites containing NaNO2 and KNO3 embedded in pores of the glasses has been investigated using small-angle neutron scattering. The characteristic sizes of magnetite particles in matrices and the sizes of nanoparticles embedded in ferroelectric materials have been estimated. It has been shown that, for microporous glasses in the momentum transfer range 0.35 nm–1 < Q < 1.7 nm–1, the dependence of the small-angle neutron scattering intensity on the momentum transfer has two characteristic regions: the first region corresponds well to the Porod’s law Q –4 (smooth surface), and the second region is consistent with the mass fractal reflecting the internal structure of channels in the microporous glass. For macroporous glasses over the entire momentum transfer range 0.35 nm–1 < Q < 1.7 nm–1, the scattering intensity is described by the dependence I(Q) ~ Q –n with α = 3.96 ± 0.02; i.e., in these glasses, there is a system of channels with sufficiently smooth surfaces.

Three neutron instruments at the Neutron Physics Laboratory (NPL) in Řež near Prague — small-angle scattering (SANS) MAUD, strain scanner SPN-100 and strain diffractometer TKSN-400 — have been modernized recently with new 2D position-sensitive detectors (PSDs) from JINR, Dubna. Here we report on the progress made in relation to the possibilities of the diffractometers due to the improved performance of the detectors. The first part of the paper is dedicated to a detailed description of the hardware and software of the PSDs, as well as its integration with the in-house experimental control software. Then practical examples of neutron scattering experiments for each of the upgraded facilities are presented.

Twist channel angular pressing (TCAP), the severe plastic deformation (SPD) technology developed recently to increase the efficiency of the imposed strain and its homogeneity within a single pass, is an effective process combining channel bending and twist extrusion in a single die. The presented study analyses the phenomena of substructure development, precipitation, structural units' orientations, and the occurrence of residual stress, as well as electric resistivity and microhardness, in commercial purity aluminium naturally aged for two years at room temperature after processing via single pass TCAP. The results are compared with the findings for the TCAP sample right after processing; selected results are also compared with the results for the sample after TCAP and one year of natural ageing, and with a sample processed by conventional ECAP. The analyses showed the substructure to recover substantially, the grain size decreased to submicron size. The residual stress within the grains introduced by the energy accumulated via the severe imposed strain relaxed significantly by the structure restoration, as well as by intensive precipitation. The aged TCAP sample specific electric resistivity was comparable to the resistivity of the original commercially pure aluminium (2.652E-05 and 2.635E-05 Ω·mm2·m−1, respectively), however, the microhardness mapping showed increased mechanical properties with homogeneous distribution.

The mechanical properties of cemented carbides can be tuned by controlling WC grain coarsening and the simultaneous growth of the binder pocket size during the sintering. So far, bulk studies considering this phenomenon are scarce, but here, we report the first very-small angle neutron scattering (VSANS) study on cemented carbides. VSANS is supplemented with electron backscatter diffraction (EBSD) and the microstructural refinement by increasing V-doping (0, 0.02, 022, and 0.76 wt%) is quantified. The capability of VSANS as a non-destructive bulk probe for cemented carbides is shown, paving way for forthcoming in-situ studies.

The heating effect in the temperature interval of 20―70 °C on the aggregate structure in aqueous ferrofluids is analyzed basing on the data of small-angle X-ray (SAXS) and neutron (SANS) scattering. Samples prepared according to the same stabilization procedure (double-layer surfactant coating) but with different dispersed magnetic materials (magnetite and cobalt ferrite) show different temperature sensitivity. A temperature-induced reorganization from developed aggregates to elongated chain-like aggregates is revealed by observing changes in the scattering curves, which are considered in the frame of the fractal concept. In addition to the determination of fractal dimension, the accent is also given to the cut-off effect in the scattering curves induced by the finite aggregate size. The scattering model is chosen from the available approaches basing on the analysis of the dimension-dependent universal parameter of the average aggregate form-factor, which continuously changes with varying temperature. The particle polydispersity is taken into account. The contrast variation based on isotope (H/D) substitution in solvent is done in SANS experiments to conclude about the structural organization of magnetic particles and surfactant component in the systems.

17NiCrMo7, 19MnCr5 and 27MnCr5 low-alloy case-hardening steels samples have been investigated by SANS (Small-Angle Neutron Scattering), to achieve data on bulk nanoscale structure characterisation and complementary analytical and crystallographic information. The reported results are related in particular to the size distribution of nanosized pores which can help to comprehend the structural basis for the physico-chemical properties and thus to improve quality and durability of the considered materials. A complementary PIXE investigation has been also carried out, with the aim of a non-destructive assessment of the elemental composition of the considered samples.

A series of samples was sintered from nanometric BaTiO 3 powder by spark plasma sintering (SPS). Porosity on ultra-fine size scales, hardly accessible for quantification by conventional techniques, was measured by small angle neutron scattering (SANS). Band gap was estimated from diffuse reflectance measurements. Sintered tablets were polished, sputtered by aluminum to create electrode system and tested in DC and AC electric fields. The results were correlated with the SPS processing parameters and are discussed in connection with other BaTiO 3 samples produced by SPS with or without additional heat treatment. Majority of our SPS fired samples had, even without subsequent thermal treatment, advantageous combination of high permittivity, DC resistivity and low loss factor, seldom reported for SPS technology.

Conventional small-angle neutron scattering (SANS) and ultrasmall-angle neutron scattering (USANS) are applied in the combined analysis of aggregated silica particles formed in basic tetraethoxysilane/ethanol/water solutions. The scattering is followed for different water/TEOS molar ratios to make a self-consistent description of fractal and size characteristics of the developed aggregates.

The evolution of distance between ω particles in metastable β Ti- 15Mo alloy (8.1 in at. %) was determined from in-situ small angle neutron scat- tering (SANS). SANS data were recorded during heating of the material from room temperature to 600 ◦C with the heating rate of 1 ◦C/min. The results agree with previously determined ordering of ω particles in a cubic three-dimensional array with the axes along the cubic axes ⟨100⟩β of the host lattice. The distance between particles, which increases with temperature, was investigated in three orientations with the incident beam parallel to [100]β, [110]β and [111]β.

A composite of powders of semi-Heusler ferromagnetic shape memory and pure titanium was successfully prepared by spark plasma sintering at the temperature of 950 °C. Sintering resulted in the formation of small precipitates and intermetallic phases at the heterogeneous interfaces. Various complementary experimental methods were used to fully characterize the microstructure. Imaging methods including transmission and scanning electron microscopy with energy dispersive X-ray spectroscopy revealed a position and chemical composition of individual intermetallic phases and precipitates. The crystalline structure of the phases was examined by a joint refinement of X-ray and neutron diffraction patterns. It was found that Co38Ni33Al29 decomposes into the B2-(Co,Ni)Al matrix and A1-(Co,Ni,Al) particles during sintering, while Al, Co and Ni diffuse into Ti forming an eutectic two phase structure with C9-Ti2(Co,Ni) precipitates. Complicated interface intermetallic structure containing C9-Ti2(Co,Ni), B2-(Co,Ni)Ti and L21-(Co,Ni)(Al,Ti) was completely revealed. In addition, C9-Ti2(Co,Ni) and A1-(Co,Ni,Al) precipitates were investigated by an advanced method of small angle neutron scattering. This study proves that powder metallurgy followed by spark plasma sintering is an appropriate technique to prepare bulk composites from very dissimilar materials.

Bulk metallic glasses (BMG) are very attractive materials exhibiting high specific strength, decent corrosion resistance and other benefiting features due to their amorphous microstructure. However, the mechanisms of mechanical properties as an issue of structure-properties relation in BMGs are not understood as well as those in polycrystalline materials. For example, the driving force for fatigue in crystalline materials is connected to grain boundary slip and the formation of dislocations i.e. to those structural elements whose existence in BMGs is still debatable. In order to find a link between the mechanical properties and the microstructure in BMG, researchers investigate structural heterogeneities i.e. clusters. The size order of the clusters and intercluster boundaries are within the resolution of small-angle neutron scattering (SANS) techniques. Here we present the results of SANS and very-small-angle neutron scattering (VSANS) studies of Zr46.75Ti8.25Cu7.5Ni10Be27.5 bulk metallic glass after deformation with and without ultrasonic vibrations. VSANS measurements revealed the creation and growth of large micropores induced by ultrasonic vibration.

International audience; We report on the self-assembly behavior of poly(2-methyl-2-oxazoline)–block–poly(2-octyl-2-oxazoline) comprising different terminal perfluoroalkyl fragments in aqueous solutions. As reported previously [Eur. Polym. J., 2017, 88, 645-655] such polyphiles can form a plethora of nanostructures depending of the composition and on the way of preparation. Here we report, for the first time, detailed information on the internal structure of the nanoparticles resulting from the self-assembly of these copolymers. Small-angle neutron and x-ray scattering (SANS/SAXS) experiments unambiguously prove the existence of polymersomes, wormlike micelles and their aggregates in aqueous solution. It is shown that increasing content of fluorine in the poly(2-oxazoline) copolymers results in a morphological transition from bilayered or multi-layered vesicles to wormlike micelles for solutions prepared by direct dissolution.In contrast, nanoparticles prepared by dialysis of a polymer solution in a non-selective organic solvent against water are characterized by SAXS method. The internal structure of the nanoparticles could be assessed by fitting of the scattering data, revealing complex core-double shell architecture of spherical symmetry. Additionally, long range ordering is identified for all studied nanoparticles due to the crystallization of the poly(2-octyl-2-oxazoline) segments inside the nanoparticles.

Peak broadening of neutron diffraction was studied at various neutron wavelengths (1.24–2.61 Å). As the neutron beam path through a specimen increased, significant peak broadening was observed in ferritic steel, but not in austenitic steel. The peak broadening was reduced under a magnetic field applied perpendicular to the beam direction. Small-angle neutron scattering results showed significant reduction in scattering intensities under a magnetic field of 1.2 T. It is suggested that the peak broadening can be attributed to multiple small-angle neutron scattering by magnetic domains. Thus, a sufficiently strong magnetic field could enhance the deep penetration capability of neutron diffraction by reducing the peak broadening.

This study is devoted to investigation of the micro- and mesostructure (including fractal properties) of porous zirconia glasses synthesized by precipitation from zirconium n-propoxide solutions in the presence of different hydrolyzing-agent (H2O) quantities at different temperatures. Analysis of small-angle neutron, ultra-small-angle neutron and X-ray scattering, scanning electron microscopy allows concluding that the synthesized glasses are complex systems with a three-level hierarchical fractal structure. It is revealed that both the temperature of synthesis and the H2O concentration in the initial solution significantly affect the structural characteristics of the glasses.

Electron beam physical vapour deposited (EB-PVD) FYSZ-coatings were produced in different morphologies by varying the process parameters. Anisotropic and isotropic nano-sized pores in these FYSZ-coatings were analysed by means of Small Angle Neutron Scattering (SANS). In order to differentiate closed and open pores, SANS-measurements were carried out as the coatings were immersed in matching liquid. With in-situ high-temperature SANS-measurements, the thermally activated changes of aspect ratio and surface area of the pores were observed. Thermal conductivity values of as-coated and aged coatings are measured by Laser-Flash Analysis (LFA) and have been correlated with the changes in pore shape and size. All results were compared to those previously obtained from standard EB-PVD PYSZ-coatings.

During superplastic deformation (SPD) of tetragonal zirconia polycrystals containing 3 mol% yttria (3Y-TZP) at high strain-rates, a number of crack-like flat cavities having very narrow gaps lying along grain boundaries mostly normal to the tensile axis are produced in addition to conventional cavities. In order to see when (from which strain point) the flat cavities get started to form, the tensile deformation of the 3Y-TZP was interrupted at different strain points including a yield point, and then a small angle neutron scattering (SANS) technique was applied to examine the existence of the flat cavities. It was found that no flat cavities were produced at the yield point but they got started to form soon after the yielding, i.e., after a superplastic flow began. The formation of the flat cavities can decrease the cross-sectional area of the specimen, resulting in a decrease in the flow stress apparently. It is therefore recommended that the formation of the flat cavities should be taken into consideration for an accurate evaluation of the flow stress in SPD at high strain-rate deformations. [doi:10.2320/matertrans.M2009381]

Thermal barrier coatings (TBCs) deposited by EB-PVD protect the turbine blades situated at the high pressure sector of the aircraft and stationary turbines increasing the combustion temperature and/or diminishing the air-cooling requirements. It is an important task to uphold low thermal conductivity in TBCs during long-term service at elevated temperatures. One of the most promising methods to fulfil this task and to improve the turbine efficiency is to optimize the TBC properties by tailoring its microstructure and/or material. The different kinds of pores in EB-PVD TBCs influence their thermal conductivity according to their size, shape, orientation and volume. These pores can be open (inter-columnar and between feather arms gaps) and closed (intra-columnar pores). Since such pores are located within three-dimensionally deposited columns and enclose large differences in their sizes, shapes, distribution and anisotropy, the accessibility for their characterization becomes very complex and requires the use of sophisticated methods. This work describes the analysis of the anisotropic and nano-sized pores in PYSZ-based TBCs by means of small angle neutron scattering (SANS) method. In order to differentiate and analyse 3D closed and open pores in 400 µm thick coatings, a contrast matching SANS technique has been employed. Thermal derived changes in crystal structure as well as pore size and morphology have been correlated with thermal conductivity.

Ex and in situ (⩽1300 °C) small-angle neutron scattering (SANS) experiments on annealed layers of air-plasma sprayed La2Zr2O7 and SrZrO3 for thermal barrier coatings are presented. The deposits exposed at 1200 °C up to 100 h showed a stable microstructure of large pores. Medium-size (≈10–50 nm) intragranular pores sinter during the exposure. The in situ SANS revealed that this process starts at 1000 °C. In contrast to La2Zr2O7, the creation of nanopores starting at 900 °C was detected in the SrZrO3 layer. These nanopores began to disappear at 1100 °C.

Superplastically deformed samples of 3 mol% yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) and 3Y-TZP with 20 wt% of Al 2 O 3 were studied by SANS with the aim to compare cavitation behaviours under different deformation conditions. Though the average size of cavities formed during deformation is so large that they can be measured only by high-resolution SANS techniques, conventional SANS method permitted us to measure their specific surface and aspect ratio quite effectively. Analysis of the two-dimentional SANS data clearly showed two qualitatively different cavitation regimes corresponding to the low-stress (low-strain rate and high-temperature) and high-stress conditions, respectively. In the latter case, a new type of flat pores transversal to the tension axis was observed, in addition to the usually present slightly prolate cavities.

Recent measurements of cavitation in superplastically strained 3Y-TZP ceramics by scanning electron microscopy and ultra small-angle neutron scattering (USANS) led to systematic differences in volume fractions of cavities determined by both methods. We show that the scattering curves measured by double crystal USANS diffractometers can be calculated directly from scanning electron micrographs taken from a single section of the material, without any assumptions of cavity shape or distribution. This technique was used to compare the USANS measurements with electron micrographs and showed that the calculated and measured curves agree well for medium scattering vectors. This result confirms that the electron micrographs represent well the microstructure of small cavities up to about 0.6 μm in radius. On the contrary, the calculations resulted in systematically larger intensities for small scattering vectors. This indicates that large cavities are responsible for the observed differences in volume fraction for the samples with nominal strain above 100%. An explanation by an inhomogeneous distribution of large cavities generated at high strains in the bulk of the tensile specimen and/or by surface artifacts is suggested.

In this paper, a fast and efficient tool for predicting a set of physical and mechanical composite properties such as thermal expansion coefficients, thermal and electrical conductivity, stiffness, and thermal residual stress is developed based on the analysis of a representative volume of ZrO2-based composite. Such an analysis allows an engineer to assess the mechanical and physical properties to design an optimum composite composition in terms of advantageous mechanical properties and at the same time a good electrical discharge machining performance. Thermal residual stresses in the constituent phases and thermal and electrical conductivity of ZrO2-based composites are assessed by a Finite Element (FE) model using 2 dimensional SEM micrographs. The FE models are verified by comparing numerically calculated results with experimentally measured data.

The Beamline for European Materials Engineering Research (BEER) will be built at the European Spallation Source (ESS). The diffractometer utilizes the high brilliance of the long-pulse neutron source and offers high instrument flexibility. It includes a novel chopper technique that extracts several short pulses out of the long pulse, leading to substantial intensity gain of up to an order of magnitude compared to pulse shaping methods for materials with high crystal symmetry. This intensity gain is achieved without compromising resolution. Materials of lower crystal symmetry or multi-phase materials will be investigated by additional pulse shaping methods. The different chopper set-ups and advanced beam extracting techniques offer an extremely broad intensity/resolution range. Furthermore, BEER offers an option of simultaneous SANS or imaging measurements without compromising diffraction investigations. This flexibility opens up new possibilities for in-situ experiments studying materials processing and performance under operation conditions. To fulfil this task, advanced sample environments, dedicated to thermo-mechanical processing, are foreseen.

We performed studies of the self-organization processes in nanoporous alumina membranes at initial and late stages of aluminum anodization by using scanning electron microscopy (SEM) and small-angle neutron scattering (SANS). SEM observations indicated three stages in the self-organization of nanopores in alumina: (1) nucleation of random nanopores with a broad radius distribution, (2) narrowing the radius distribution and (3) slow evolution of the nanoporous structure towards ordering of nanopores into large domains. SANS studies revealed orientational correlation between ordered domains of nanopores, which is characterized by a small misorientation angle. For the samples with high aspect ratios of nanopores, the SANS patterns showed azimuthal smearing, which was attributed to the redistribution of nanopores between the domains during their growth.

We present here results of small-angle neutron scattering (SANS) investigation of partially and fully yttria stabilized zirconia (PYSZ and FYSZ, respectively) turbine blade coatings (TBC). The samples have been prepared by electron beam physical vapour deposition method (EB-PVD) with various setup parameters. Structure parameters of porosity have been studied in-situ with high-temperature furnace. Temperature dependence of specific surface and anisotropy parameter of porosity has been obtained. Differences in character of microstructural morphology changing with in-situ thermal treatment as well as open and closed porosity ratio in PYSZ and FYSZ has been described and discussed.

Small-angle scattering functions in an infinite-slit geometry can be calculated directly from an image of a sample section through the scattering plane without particular assumptions about material isotropy. The method was tested on simulated images with the aim of assessing qualitatively the precision of direct comparisons of electron-microscopy images with double-crystal SANS data. The results for images of 10242 pixels show that such calculations are reliable particularly in the central part of scattering curves and for objects with radii between about 5 and 100 pixels. For the large-Q region, substantial systematical errors due to boundary effects should be avoided by taking a sufficiently large image area compared to the dimensions of the scattering objects.