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An increasing demand for products and services in the aviation industry is attended by a rising demand for aircraft engines. This requires an increased productivity combined with highest quality and safety standards. In this paper, a new approach of material defect detection is presented which is based on force and acoustic-emission measurements during machining processes. Representative synthetic defects in titanium alloy Ti6246 were investigated. In order to use scale effects, the experiments were conducted in micro-milling processes. This approach could be used for an automated, non-destructive evaluation of the manufactured components in the future and thus for reducing testing effort and related auxiliary times.

The development of thin-film thermoelectric applications in sensing and energy harvesting can benefit largely from suitable deposition methods for earth-abundant materials. In this study, p-type copper oxide thin films have been prepared on soda lime silicate glass by direct current (DC) magnetron sputtering at room temperature from a pure copper metallic target in an argon atmosphere, followed by subsequent annealing steps at 300 °C under various atmospheres, namely air (CuO:air), nitrogen (CuO:N) and oxygen (CuO:O). The resultant films have been studied to understand the influence of various annealing atmospheres on the structural, spectroscopic and thermoelectric properties. X-ray diffraction (XRD) patterns of the films showed reflexes that could be assigned to those of crystalline CuO with a thin mixed Cu(I)Cu(II) oxide, which was also observed by near edge X-ray absorption fine structure spectroscopy (NEXAFS). The positive Seebeck coefficient (S) reached values of up to 204 μV K−1, confirming the p-type behavior of the films. Annealing under oxygen provided a significant improvement in the electrical conductivity up to 50 S m−1, resulting in a power factor of 2 μW m−1 K−2. The results reveal the interplay between the intrinsic composition and the thermoelectric performance of mixed copper oxide thin films, which can be finely adjusted by simply varying the annealing atmosphere.

The runout of milling tools results in uneven effective tooth radii and affects the occurrence of tool wear in machining processes. The load and, thus, the specific wear of teeth with increased effective radii is higher. In processes with small undeformed chip thicknesses, e.g., the finishing of titanium alloys, the runout error could even be greater than the undeformed chip thickness. In this case, at least one cutting edge does not remove any material. In this paper, the influence of the runout on wear effects is analyzed for an exemplary finishing process using cutting force measurements and a geometric physically-based process simulation.

This work reports laboratory angle resolved measurements with the goal of establishing laboratory techniques to obtain a more complete idea of the intralayer composition of multilayer samples. While X-ray reflectometry is a widely available technique for the characterization of multilayer samples, angle resolved XRF measurements (grazing emission/incidence X-ray fluorescence) are usually performed at synchrotron radiation facilities. With the development of efficient laboratory spectrometers and evaluation algorithms for angle resolved measurements, these methods become suited for routine measurements and screening. We present two laboratory spectrometers which make quantitative non-destructive elemental depth profiling feasible. For reasons of comparison a validation sample, a nickel–carbon multilayer sample, is measured with both setups and additional information on krypton contamination and its distribution is retrieved. Additionally, the first application for the characterization of multilayer structures with sub-nanometer layer thicknesses is shown.

Efficient soft X-ray spectroscopy in the laboratory is still a challenging task. Here, we report on new toroidal multilayer optics designed and applied with the laser-produced plasma (LPP) source of the Berlin Laboratory for innovative X-ray technologies. The optics are described and characterized, and the application of the updated source to scanning-free grazing emission X-ray fluorescence is demonstrated on thermoelectric gold-doped copper oxide nanofilms. The comparison with synchrotron measurements allows estimating a flux on the sample of approximately 7.5 × 109 photons/s in the 1 keV range on a 100 µm × 100 µm spot, emphasizing the suitability of the updated LPP source for the application in photon hungry experiments. K.B. is most grateful for the scholarship from the International Max-Planck Research School at the Fritz Haber Institute. J.B. would like to thank the Excellence Initiative of the Deutsche Forschungsgemeinschaft for financial support.

In principle, most X-ray sensitive pixelated detectors like CCDs or active pixel sensors (e.g. CMOS detectors) can be operated in single-photon counting (SPC) mode. In combination with rather simple data post-processing steps, this allows the exploitation of energy-dispersive properties similar to hybrid-pixel detectors and pnCCDs. For example, energy discrimination can be used to simultaneously measure the spatial distribution of various fluorescence lines on the detector chip or enable noise suppression in wavelength-dispersive measurements. Furthermore, due to the analysis of the charge distribution on the detector resulting from an absorbed X-ray photon, sub-pixel spatial resolution can be achieved. Where applicable, those additional features can be utilized without any hardware modification at the detector. There is a large potential for novel experiments and sensitivity gain in many laboratories already applying pixelated detectors, but only a few experiments indeed use this potential. The up until now published algorithms are hardly validated and rarely described in detail. Besides a thorough description of various algorithms for photon event evaluation, this work concentrates on a quantitative and qualitative comparison of such algorithms with respect to energy resolution, efficiency and photon recovery. For this purpose, the algorithms are tested on simulated data featuring various detector noise and charge-cloud size values and the influence of noise thresholds and photon density is discussed. Finally, we present two examples to demonstrate the advantages of photon event evaluation and highlight its benefits for X-ray spectroscopic applications.

An angle resolved X-ray fluorescence spectrometer based on the concept of scanning-free shallow detection with energy-dispersive area detectors is presented. The instrument is characterized with respect to energy resolution, linearity, angular discrimination and repeatability and the necessary data evaluation strategies are presented in detail. As demonstration of its capabilities and showcase for potential applications, two different copper indium gallium (di)selenide (CIGS) absorber layers, typically applied in thin film solar cells, are analyzed. In combination with quantitative (but integral) results for layer composition and layer thickness from a commercial XRF spectrometer, depth profiles of the Ga concentration of both ≈ 2 μm thin samples are obtained. The results of the novel spectrometer compare well with quantitative depth-profiles obtained from glow-discharge optical emission spectrometry. The combination of simplicity, stability and efficiency of the spectrometer concept makes it a potential candidate for industrial applications. Description of compact angle-resolved X-ray fluorescence spectrometer. Exploiting scanning-free grazing emission X-ray fluorescence approach. Energy dispersive charge-coupled device with single-photon detection. Enabling non-destructive, quantitative elemental depth profiling. Depth profiling of nano-structured stratified specimen, here CIGS solar cells.

Efficient multilayer optics for radiation in the water window range are difficult to manufacture due to extremely small layer thicknesses and severe intermixing of elements between the layers. Therefore, adequate analytics and short feedback loops are of utmost importance for manufacturers to improve performance and efficiency. We show the possibility for non-destructive elemental depth profiling with commercial laboratory equipment using four real-life CrSc multilayer samples. Comparative measurements at the laboratory of PTB at the synchrotron radiation facility BESSY II confirm the results and prove the potential of laboratory equipment for the reliable analysis of stratified materials with sub-nanometer layer thicknesses.

A flexible spectrograph for the investigation of soft X-ray spectra in the range between 1 nm and 20 nm is presented. Based on two variable-line spaced reflection gratings, the design enables stand-alone operation, the change between the use of an entrance slit and a slitless operation mode as well as a maximum compactness and robustness due to a reduced number of motorized stages. Characterization measurements as well as first proof-of-principle X-ray emission investigations show the potential of the instrument for versatile applications.A flexible spectrograph for the investigation of soft X-ray spectra in the range between 1 nm and 20 nm is presented. Based on two variable-line spaced reflection gratings, the design enables stand-alone operation, the change between the use of an entrance slit and a slitless operation mode as well as a maximum compactness and robustness due to a reduced number of motorized stages. Characterization measurements as well as first proof-of-principle X-ray emission investigations show the potential of the instrument for versatile applications.

International audience; Manufacturing of nanomaterials (NMs) is often complex and expensive, and their environmental risks are poorly understood or even unknown. An economization of testing NMs is therefore desirable, which can be achieved by miniaturizing test systems. However, the downsizing of test vessels and volumes can enlarge the surface/volume ratio (SVR) which in turn can affect the bioavailable concentration of adsorbing substances like NMs. The present study focused on the miniaturization of the acute toxicity test with Daphnia magna. The adaptations were verified with three reference substances, the non-adsorbing potassium dichromate (K2Cr2O7) and as potentially highly-adsorbing substances silver nanoparticles (AgNPs) and silver nitrate (AgNO3). The miniaturized test was conducted in 24-well microtiter plates (MT) and simultaneously compared to the OECD standard test (ST). Furthermore, the test duration was prolonged from 48 to 96 h since NMs tend to show effects only after extended exposure. The toxicity of K2Cr2O7 and AgNPs continued to increase within the prolonged test span. The test comparisons with K2Cr2O7 did not reveal any significant differences between ST and MT. AgNO3 toxicity was significantly decreased in MT compared to ST due to the enlarged SVR. The toxicity of AgNPs in MT after 24 h was equal to ST. Contrary to our expectations an exposure longer than 24 h resulted in an increase of AgNP toxicity in MT, possibly due to enhanced dissolution of silver. Microtiter plates are appropriate alternative test vessels for the Daphnia sp. acute toxicity test; thus, its miniaturization is feasible. The enlarged SVR has to be taken into account since it can affect the toxicity of potentially adsorbing substances. Furthermore, the standard test duration of 48 h might underestimate the toxicity of many substances, especially of NMs.