This study aims to investigate the effect of varying plasma nitriding intensities, followed by coating and the light grinding step (between the nitriding and coating), which is designed to enhance the adhesion properties of L-PBF 18Ni300 maraging steel. Adhesion performance was evaluated using Rockwell indentation and scratch testing. More intense plasma nitriding significantly improves surface hardening and thickness of the diffusion layer, thereby increasing load-bearing capacity and reducing coating delamination. The surface hardening provided by the presence of Fe4N and Mo2N precipitates was observed by detailed TEM observation. The sample subjected to soft grinding exhibited acceptable adhesion in indentation tests but demonstrated lower adhesion in scratch tests. This discrepancy is due to the different loading modes and sensitivity to interfacial features between the indentation and scratch tests. The presence of interfacial oxides, steep residual stress gradient, and relatively low surface roughness compromised adhesion under scratch testing. Anisotropic behaviour was also observed. In intense nitrided and ground samples, scratch testing along the parallel direction resulted in better adhesion compared to the perpendicular one. This work highlights that coating adhesion in duplex-treated L-PBF maraging steels is not solely controlled by hardness and diffusion layer thickness, but is also strongly influenced by microstructure of the interface, surface roughness, residual stresses and build direction. Overall, the intensely nitrided and coated sample has demonstrated the best adhesion performance, considering both testing methods.

Mine optimisation and anticipation of ore behaviour in the mineral processing and separation circuits are major economic drivers for all mining operation. Recent methodological developments with the inception of geometallurgy across multiple commodities has highlighted the importance of mineralogy in addition to grades. Since several decades, many quantitative tools have been developed, mostly SEM-based such as QEMSCAN®, to provide quantitative mineralogical composition and textural properties of ore and gangue samples. We aim to compare the more established SEM-based techniques to the Solsa combined XRD-XRF analyser to highlight their respective potential and limitations depending on the minerals and goals of the mining operators. The combined XRF-XRD of the SOLSA analytical solution brings a new methodology able to produce quantitative mineralogical and geochemical data at a speed compatible with routine data collection, from exploration to quality control on the different streams of minerals in a processing plant.

In this work, we propose an X-ray diffraction characterization of the flax ultrastructure to improve our understanding of its role in expressing the complex mechanical behaviour of flax fibres. Initially, X-ray diffraction measurements were performed on both undeformed and deformed samples consisting in fibre bundles and using for the first time, the combined “structure/microstructure/texture” analysis method implemented in the Maud software and based on a Rietveld algorithm. For all the fibre bundles, the microstructural analysis showed that these microfibrils, having a cellulose Iβ structure, exhibit an ellipsoidal crystallite shape elongated along their c-axis. The results also suggest the existence of a paracrystalline cellulose phase in the flax ultrastructure, with a degree of order intermediate between amorphous and crystalline Iβ cellulose. The corresponding quantitative texture analysis allowed to access the microfibril angle distribution in the flax secondary wall, with cellulose microfibrils inclined with respect to fibre axes with angles in the 0–20° range and a maximum of the distribution around 5°–10°. The combination of tensile tests and in-situ X-ray diffraction measurements put in evidence a substantial rearrangement of the microfibril angle distribution confirming the reorientation of cellulose microfibrils along the fibre axis. However, this evolution is non-linear and appears significant for deformations below 0.6

Nanocrystalline (NC) materials have widespread industrial usage. X-ray and neutron diffraction techniques are primary tools for studying the structural and microstructural features of NC materials. Selected area electron diffraction (SAED) patterns collected using a transmission electron microscope (TEM) on polycrystalline nanostructured materials, featuring nested rings, that are analogous to Debye-Scherrer patterns, possess similar potentials to aid materials characterisation. The utility of SAED patterns is further enhanced by the possibility of applying crystallographic approaches, like full pattern fitting procedures, based on Rietveld refinement algorithms, enabling the evaluation of material features, such as crystallite size, lattice distortions, defect structures, and the presence of secondary phases even from very small volume scale. In this paper, we have discussed the possibilities afforded by a Rietveld code applied to SAED patterns of NC materials, including the mathematical implementation of the two-beam dynamical correction model in MAUD software (version 2.9995), and a critical discussion of the results obtained on different NC materials.

Neutron diffraction beamlines have traditionally relied on deploying large detector arrays of 3He tubes or neutron-sensitive scintillators coupled with photomultipliers to efficiently probe crystallographic and microstructure information of a given material. Given the large upfront cost of custom-made data acquisition systems and the recent scarcity of 3He, new diffraction beamlines or upgrades to existing ones demand innovative approaches. This paper introduces a novel Timepix3-based event-mode imaging neutron diffraction detector system as well as first results of a silicon powder diffraction measurement made at the HIPPO neutron powder diffractometer at the Los Alamos Neutron Science Center. Notably, these initial measurements were conducted simultaneously with the 3He array on HIPPO, enabling direct comparison. Data reduction for this type of data was implemented in the MAUD code, enabling Rietveld analysis. Results from the Timepix3-based setup and HIPPO were benchmarked against McStas simulations, showing good agreement for peak resolution. With further development, systems such as the one presented here may substantially reduce the cost of detector systems for new neutron instrumentation as well as for upgrades of existing beamlines.

Modern diffraction experiments (e.g. in situ parametric studies) present scientists with many diffraction patterns to analyze. Interactive analyses via graphical user interfaces tend to slow down obtaining quantitative results such as lattice parameters and phase fractions. Furthermore, Rietveld refinement strategies (i.e. the parameter turn-on-off sequences) tend to be instrument specific or even specific to a given dataset, such that selection of strategies can become a bottleneck for efficient data analysis. Managing multi-histogram datasets such as from multi-bank neutron diffractometers or caked 2D synchrotron data presents additional challenges due to the large number of histogram-specific parameters. To overcome these challenges in the Rietveld software Material Analysis Using Diffraction (MAUD), the MAUD Interface Language Kit (MILK) is developed along with an updated text batch interface for MAUD. The open-source software MILK is computer-platform independent and is packaged as a Python library that interfaces with MAUD. Using MILK, model selection (e.g. various texture or peak-broadening models), Rietveld parameter manipulation and distributed parallel batch computing can be performed through a high-level Python interface. A high-level interface enables analysis workflows to be easily programmed, shared and applied to large datasets, and external tools to be integrated with MAUD. Through modification to the MAUD batch interface, plot and data exports have been improved. The resulting hierarchical folders from Rietveld refinements with MILK are compatible with Cinema: Debye-Scherrer, a tool for visualizing and inspecting the results of multi-parameter analyses of large quantities of diffraction data. In this manuscript, the combined Python scripting and visualization capability of MILK is demonstrated with a quantitative texture and phase analysis of data collected at the HIPPO neutron diffractometer.

There is a growing interest in on-site, real-time analytical solutions for mining and environmental projects to characterize large areas and/or volumes of raw materials that are sometimes highly heterogeneous in terms of elemental distribution and mineralogy. Several fast and cost-effective methods are used for rapid on-site screening and real-time chemical and mineralogical characterization, such as portable X-ray fluorescence (pXRF) and X-ray diffraction (pXRD). However, these methods are not always applicable due to limitations in the detection and quantification of light elements (Mg, Al, Si) for pXRF or complex or minor minerals for pXRD, whose results need to be supported by laboratory analysis. This study presents a new methodological approach for in situ rapid chemical and mineralogical characterization of samples, based on the use of a transportable instrument (called ID2B) that allows, in a single acquisition step, a combined XRD-XRF analysis to identify and quantify the chemical elements and their associated minerals. The HI0 harzburgite sample from New Caledonia used to evaluate the data was analyzed in the laboratory (SEM-EDS, EPMA, XRF and XRD) and with the ID2B instrument to highlight the potential of our new methodology. In order to demonstrate the interest of using the ID2B combined XRF-XRD analysis approach directly in the field, where sample preparation is not always easy to implement, this comparison was made on the same sample (HI0), prepared in two different ways, either as a powderized (optimal preparation) or as-sawn (unprepared) sample. After automated processing of the combined XRF-XRD datasets acquired with the ID2B instrument, the chemical elements and mineralogical phases identified on both the powder and as-sawn samples are identical to the laboratory analyses. The chemical proportions calculated from the combined XRF-XRD data sets are also close to the laboratory XRF analysis with relative errors <5 % for Al, Mg and Si and even closer for Ca, Cr, Mn, Ni and Fe. The variability in the calculated chemical proportions is attributed to the sample heterogeneity highlighted by the mineral proportions that vary slightly between the laboratory XRD and XRD ID2B analyses of the powder, and more pronounced for the as-sawn XRD ID2B analysis. These observations show that the combined XRF-XRD approach performed on powder and as-sawn samples provides accurate chemical and mineralogical results to those obtained in the laboratory. The deployment of this new methodological approach directly on the field can provide valuable chemical and mineralogical analyses.

Mine optimisation and anticipation of ore behaviour in the mineral processing and separation circuits are major economic drivers for all mining operations. Recent methodological developments with the inception of geometallurgy across multiple commodities have highlighted the importance of mineralogy in addition to elemental grades. In the last few decades, many quantitative tools have been developed, mostly SEM-based such as QEMSCAN®, and used to provide the quantitative mineralogical compositions of samples. Their main drawback is the time and cost associated with sample preparation, acquisition time, and data QA/QC. The combined XRF-XRD of the SOLSA (Sonic On-Line drilling and Sampling Analysis) analytical solution brings a new methodology able to produce quantitative mineralogical and geochemical data at a speed compatible with a production environment. Its range of applications covers the entire life of a mining operation, from the initial exploration stage to mineral processing control, as well as waste management and environmental monitoring.

A compact detection module for the simultaneous measurement of XRF and XRD in portable analytical applications, in particular in the mining sector, is presented. The detector head is based on 32 silicon strip detectors, fabricated with a low-leakage technology by FBK and readout by two 16-channel low-noise CUBE charge-sensitive amplifiers. The design of the module and its characterization are reported. Multiple configurations are experimentally compared in terms of strip length, spacing, collimation and charge sharing effects. The optimal configuration for a strip length of 6 mm and pitch 0.2 mm is thus identified. It offers an energy resolution of better than 200 eV at 5.9 keV with moderate cooling (−10°C) and peaking time of 14 μs.

Transmission electron microscopy is a powerful experimental tool, very effective for the complete characterization of nanocrystalline materials by employing a combination of imaging, spectroscopy and diffraction techniques. Electron powder diffraction (EPD) pattern fingerprinting in association with chemical information from spectroscopy can be used to deduce the identity of the crystalline phases. Furthermore, EPD has similar potential to X-ray powder diffraction (XRPD) for extracting additional information regarding material specimens, such as microstructural features and defect structures. The aim of this paper is to extend a full-pattern fitting procedure, broadly used for analysing XRPD patterns, to EPD. The interest of this approach is twofold: in the first place, the relatively short times involved with data acquisition allow one to speed up the characterization procedures. This is a particularly interesting aspect in the case of metastable structures or kinetics studies. Moreover, the reduced sampling volumes involved with electron diffraction analyses can better reveal surface alteration layers in the analysed specimen which might be completely overlooked by conventional bulk techniques. The first step forward to have an effective application of the proposed methodology concerns establishing a reliable calibration protocol to take into correct account the instrumental effects and thus separate them from those determined by the structure, microstructure and texture of the analysed samples. In this paper, the methodology for determining the instrumental broadening of the diffraction lines is demonstrated through a full quantitative analysis based on the Rietveld refinement of the EPD. In this regard, a CeO2 nanopowder reference specimen has been used. The results provide indications also on the specific features that a good calibration standard should have.

Powder diffraction is a non-destructive technique, which is experimentally simple in principle. Because the physics behind diffraction is well understood, an exceptionally large amount of information can be obtained from a single measurement. The positions and relative intensities of the peaks yield a fingerprint that can be used for qualitative phase analysis. Quantitative phase analysis can be obtained by detailed analysis of the intensities. Unit cells can be derived from the peak positions. Crystal structures can be solved using powder diffraction data and refined by the Rietveld method. The peak profiles contain information about crystallite size, strain and nanostructure. Non-idealities in the intensities give information on texture. Abandoning the crystallographic model provides information about local structure, by pair distribution function analysis. For powder diffraction, everything is a sample; the technique is commonly applied to characterize minerals, ceramics, metals and alloys, catalysts, polymers, pharmaceuticals, organic compounds, environmental and forensic samples, among others. The major features of contemporary laboratory powder diffractometers are described. Methods for obtaining suitable powder specimens are summarized. Major applications of qualitative and quantitative phase analysis, structure solution, size/strain/nanostructure analysis using peak profiles, texture analysis and pair distribution function analysis are introduced.

While structure refinement is routinely achieved for simple bulk materials, the accurate structural determination still poses challenges for thin films due on the one hand to the small amount of material deposited on the thicker substrate and, on the other hand, to the intricate epitaxial relationships that substantially complicate standard X-ray diffraction analysis. Using a combined approach, we analyze the crystal structure of epitaxial LaVO3 thin films grown on (100)-oriented SrTiO3. Transmission electron microscopy study reveals that the thin films are epitaxially grown on SrTiO3 and points to the presence of 90 oriented domains. The mapping of the reciprocal space obtained by high resolution X-ray diffraction permits refinement of the lattice parameters. We finally deduce that strain accommodation imposes a monoclinic structure onto the LaVO3 film. The reciprocal space maps are numerically processed and the extracted data computed to refine the atomic positions, which are compared to those obtained using precession electron diffraction tomography. We discuss the obtained results and our methodological approach as a promising thin film structure determination for complex systems.

Dans le cadre du projet europeen SOLSA, le BRGM et le CRISMAT, participent au developpement d’un banc d’expertise multi-capteurs (SOLSA ID2A-ID2B). L’enjeu majeur de SOLSA, est d’apprehender l’approche d’un geologue de terrain sur des echantillons afin de permettre une retranscription de son savoir sous forme d’algorithmes intelligents. Dans ce contexte, un echantillon prepare sous trois formes (poudre, lame mince et echantillon brut) a ete selectionne dans cette etude. Il s’agit d’une harzburgite serpentinisee. L’echantillon a d’abord ete caracterise en laboratoire (fluorescence X, ICP-AES, et diffraction des rayons X) puis analyse sous ces differentes preparations sur SOLSA ID2B. Cette etude a permis de montrer que l’approche de terrain admet des resultats similaires aux resultats obtenus en laboratoire mais avec une rentabilite plus elevee. En comparant les resultats obtenus sur les trois types de preparation, il a ete demontre que l’influence de la preparation de l’echantillon est mineure sur les resultats combines FluoX-DRX. Enfin, par la creation d’algorithme permettant la superposition d’image RVB et la distribution spatiale des elements chimiques (Fig 1), il a ete possible d’ameliorer la connaissance des substitutions au sein des phases presentes, la localisation de certains elements dans des zones preferentielles et les correlations elements/elements et phases/elements.

Polypropylene (PP) represents one of the most worldwide used plastics with a large variety of products and applications. As usual for semicrystalline polymers, the properties of PP products strictly depend on the processing (fiber spinning, film extrusion, injection, etc.), where orientation and crystallization phenomena are involved. The object of this communication is the mechanical and structural characterization of oriented products from iPP homopolymers, i.e., injection molded dumbbell specimens (IM), lab-scale single fibers and commercial bulk continuous filament (BCF), woven non-woven fabrics (WNW) by using differential scanning calorimetry (DSC), dynamical mechanical thermal analysis (DMTA), tensile measurements, and X-ray diffraction (XRD) analysis. In particular, a recent methodology to analyze diffraction images of oriented polymers to obtain crystal structure, texture, and microstructural information is presented. The higher the orientation, the higher the mechanical properties and the sharper the texture, as revealed by a quantitative texture analysis that has been also developed and successfully applied to oriented PP nanocomposites.

Summary SOLSA is the first automated expert system for on-site cores analysis. The scope is to provide a prototype to be an innovative and necessary tool for geo-metallurgy, in order to optimize the valorization of the ore. The Expert System consists in the combination of an integrated drilling rig providing cores of high quality, an automated scanner and phase identification software, developed for nickel laterites and bauxites but usable as well in other sectors. SOLSA combines non-destructive sensors and the whole system is driven by an innovative, user-friendly and intelligent software. SOLSA provides more complete information while optimizing the exploration stage, with a significant reduction of costs and return time. Such objective involves, in the first place, to fast, cheaper and systematic acquisition of the data needed for optimizing the process. The adding value takes place first at the exploration or grade control stage, furnishing systematic characterization and regionalization of the different types of ore. Then such information can be used for improving the ore scheduling at the mining and processing stages, toward improving the recovery and efficiency of the processing.

We present the design and characterization of a detection unit for simultaneous and combined XRF and XRD analysis of powder mineralogical samples. Arrays of 32 silicon microstrips are coupled to two 16-channel CUBE preamplifiers targeting an energy resolution below 200 eV at 6 keV with moderate cooling. The compact detection module will be mounted on a goniometer inside a suitcase-sized analyzer to be operated in mining sites.

The information provided by material investigations on ancient coins is interesting in many respects, as concerns the archaeological and historical research. In this study a set of Venetian sesino coins, minted over a period ranging from 1554 until 1605, have been investigated in order to shed light on some aspects of the so‐called mistura (mixture) alloy. The widespread diffusion of these relatively low‐value coins of the Venetian Republic, commonly used in commercial transactions in the second half of 16th century, also outside the territories of the Republic, makes them an important proxy to be used in the reconstruction of the political and historical events of the period. The specific issue of the actual composition of the mistura alloy is herewith addressed for the first time, using a combined approach based on X‐ray fluorescence and X‐ray diffraction nondestructively applied to the analysis of the samples. It turns out that the mistura alloy, traditionally regarded as a Cu‐Ag two phase alloy, over the latest period of circulation of the sesino coins, was actually made of copper only, still containing minor concentrations of lead, to be regarded as an impurity of the alloy and not as an intentional addition.

The material study of ancient coins is very often rendered particularly challenging by several factors: the presence of surface alteration products; the occasional or deliberate, e.g., forgery, changes in the composition of the base alloy; the misleading information deriving from historical and literature sources. We present herewith a multi-analytical approach to the study of ancient coins. The selected test samples are coins widely used in the Venetian Republic over a time span ranging from the second half of the 16th until the early years of the 17th century: the so-called “sesino”. The rationale of the study was to establish a model, taking into account the layered structure of the surface region of the coins, that once validated could be used for a fully non-destructive characterization of similar items. The specific interest of the results obtained from this investigation is twofold. First, the actual composition of the copper based alloy used for these specific type of Venetian coin, has been measured for the first time with direct measurements on the coin cross-section. Second, the detailed characterization of the coins provides an essential background knowledge for a fully non-destructive characterization of the same kind of coins.